Seal implicitly used classes (#309)

Apparently the `[UsedImplicitly]` annotation suppresses the "Class has
no inheritors and can be marked sealed" warning. Cool to know.

Signed-off-by: Octol1ttle <l1ttleofficial@outlook.com>

TeamOctolings.Octobot/Commands/AboutCommandGroup.cs

@@ -25,7 +25,7 @@ namespace TeamOctolings.Octobot.Commands;
 ///     Handles the command to show information about this bot: /about.
 /// </summary>
 [UsedImplicitly]
-public class AboutCommandGroup : CommandGroup
+public sealed class AboutCommandGroup : CommandGroup
 {
     private static readonly (string Username, Snowflake Id)[] Developers =
     [
@@ -36,9 +36,9 @@ public class AboutCommandGroup : CommandGroup
 
     private readonly ICommandContext _context;
     private readonly IFeedbackService _feedback;
+    private readonly IDiscordRestGuildAPI _guildApi;
     private readonly GuildDataService _guildData;
     private readonly IDiscordRestUserAPI _userApi;
-    private readonly IDiscordRestGuildAPI _guildApi;
 
     public AboutCommandGroup(
         ICommandContext context, GuildDataService guildData,

TeamOctolings.Octobot/Commands/BanCommandGroup.cs

@@ -26,7 +26,7 @@ namespace TeamOctolings.Octobot.Commands;
 ///     Handles commands related to ban management: /ban and /unban.
 /// </summary>
 [UsedImplicitly]
-public class BanCommandGroup : CommandGroup
+public sealed class BanCommandGroup : CommandGroup
 {
     private readonly AccessControlService _access;
     private readonly IDiscordRestChannelAPI _channelApi;

TeamOctolings.Octobot/Commands/ClearCommandGroup.cs

@@ -23,7 +23,7 @@ namespace TeamOctolings.Octobot.Commands;
 ///     Handles the command to clear messages in a channel: /clear.
 /// </summary>
 [UsedImplicitly]
-public class ClearCommandGroup : CommandGroup
+public sealed class ClearCommandGroup : CommandGroup
 {
     private readonly IDiscordRestChannelAPI _channelApi;
     private readonly ICommandContext _context;

TeamOctolings.Octobot/Commands/Events/ErrorLoggingPostExecutionEvent.cs

@@ -18,7 +18,7 @@ namespace TeamOctolings.Octobot.Commands.Events;
 ///     Handles error logging for slash command groups.
 /// </summary>
 [UsedImplicitly]
-public class ErrorLoggingPostExecutionEvent : IPostExecutionEvent
+public sealed class ErrorLoggingPostExecutionEvent : IPostExecutionEvent
 {
     private readonly IFeedbackService _feedback;
     private readonly ILogger<ErrorLoggingPostExecutionEvent> _logger;

TeamOctolings.Octobot/Commands/Events/LoggingPreparationErrorEvent.cs

@@ -11,7 +11,7 @@ namespace TeamOctolings.Octobot.Commands.Events;
 ///     Handles error logging for slash commands that couldn't be successfully prepared.
 /// </summary>
 [UsedImplicitly]
-public class LoggingPreparationErrorEvent : IPreparationErrorEvent
+public sealed class LoggingPreparationErrorEvent : IPreparationErrorEvent
 {
     private readonly ILogger<LoggingPreparationErrorEvent> _logger;
 

TeamOctolings.Octobot/Commands/InfoCommandGroup.cs

@@ -23,7 +23,7 @@ namespace TeamOctolings.Octobot.Commands;
 ///     Handles info commands: /userinfo, /guildinfo.
 /// </summary>
 [UsedImplicitly]
-public class InfoCommandGroup : CommandGroup
+public sealed class InfoCommandGroup : CommandGroup
 {
     private readonly ICommandContext _context;
     private readonly IFeedbackService _feedback;

TeamOctolings.Octobot/Commands/KickCommandGroup.cs

@@ -22,7 +22,7 @@ namespace TeamOctolings.Octobot.Commands;
 ///     Handles the command to kick members of a guild: /kick.
 /// </summary>
 [UsedImplicitly]
-public class KickCommandGroup : CommandGroup
+public sealed class KickCommandGroup : CommandGroup
 {
     private readonly AccessControlService _access;
     private readonly IDiscordRestChannelAPI _channelApi;

TeamOctolings.Octobot/Commands/MuteCommandGroup.cs

@@ -26,7 +26,7 @@ namespace TeamOctolings.Octobot.Commands;
 ///     Handles commands related to mute management: /mute and /unmute.
 /// </summary>
 [UsedImplicitly]
-public class MuteCommandGroup : CommandGroup
+public sealed class MuteCommandGroup : CommandGroup
 {
     private readonly AccessControlService _access;
     private readonly ICommandContext _context;

TeamOctolings.Octobot/Commands/PingCommandGroup.cs

@@ -22,7 +22,7 @@ namespace TeamOctolings.Octobot.Commands;
 ///     Handles the command to get the time taken for the gateway to respond to the last heartbeat: /ping
 /// </summary>
 [UsedImplicitly]
-public class PingCommandGroup : CommandGroup
+public sealed class PingCommandGroup : CommandGroup
 {
     private readonly IDiscordRestChannelAPI _channelApi;
     private readonly DiscordGatewayClient _client;

TeamOctolings.Octobot/Commands/RemindCommandGroup.cs

@@ -25,13 +25,13 @@ namespace TeamOctolings.Octobot.Commands;
 ///     Handles commands to manage reminders: /remind, /listremind, /delremind
 /// </summary>
 [UsedImplicitly]
-public class RemindCommandGroup : CommandGroup
+public sealed class RemindCommandGroup : CommandGroup
 {
     private readonly IInteractionCommandContext _context;
     private readonly IFeedbackService _feedback;
     private readonly GuildDataService _guildData;
-    private readonly IDiscordRestUserAPI _userApi;
     private readonly IDiscordRestInteractionAPI _interactionApi;
+    private readonly IDiscordRestUserAPI _userApi;
 
     public RemindCommandGroup(
         IInteractionCommandContext context, GuildDataService guildData, IFeedbackService feedback,

TeamOctolings.Octobot/Commands/SettingsCommandGroup.cs

@@ -26,7 +26,7 @@ namespace TeamOctolings.Octobot.Commands;
 ///     Handles the commands to list and modify per-guild settings: /settings and /settings list.
 /// </summary>
 [UsedImplicitly]
-public class SettingsCommandGroup : CommandGroup
+public sealed class SettingsCommandGroup : CommandGroup
 {
     /// <summary>
     ///     Represents all options as an array of objects implementing <see cref="IGuildOption" />.

TeamOctolings.Octobot/Commands/ToolsCommandGroup.cs

@@ -22,7 +22,7 @@ namespace TeamOctolings.Octobot.Commands;
 ///     Handles tool commands: /random, /timestamp, /8ball.
 /// </summary>
 [UsedImplicitly]
-public class ToolsCommandGroup : CommandGroup
+public sealed class ToolsCommandGroup : CommandGroup
 {
     private static readonly TimestampStyle[] AllStyles =
     [