Correct issue label names per recent changes (#160)

Issue labels have been reworked recently, causing some files in
`.github` to reference non-existing issue labels. This PR updates the
names of labels in these files.

.github/dependabot.yml

@@ -13,7 +13,8 @@ updates:
       # Allow both direct and indirect updates for all packages
       - dependency-type: "all"
     labels:
-      - "type: dependencies"
+      - "type: change"
+      - "area: build/ci"
 
   - package-ecosystem: "nuget" # See documentation for possible values
     directory: "/" # Location of package manifests
@@ -23,4 +24,5 @@ updates:
       # Allow both direct and indirect updates for all packages
       - dependency-type: "all"
     labels:
-      - "type: dependencies"
+      - "type: change"
+      - "area: build/ci"