ci: add labels for GitHub Actions dependabot updates

Adds labels for GitHub Actions Dependabot pull requests in .github/dependabot.yml.

Signed-off-by: Ayush More <ayushmore42595@gmail.com>

Author: Ayushmore1214

.github/dependabot.yml

@@ -81,3 +81,7 @@ updates:
     directory: "/"
     schedule:
       interval: "weekly"
+    labels:
+      - dependencies
+      - github-actions
+      - area/build