chore(dependabot): Add v3 label (#3698)

.github/dependabot.yml

@@ -5,8 +5,8 @@
 
 version: 2
 updates:
-  - package-ecosystem: "pip" # See documentation for possible values
-    directory: "/" # Location of package manifests
+  - package-ecosystem: "pip"
+    directory: "/"
     schedule:
       interval: "weekly"
     target-branch: master
@@ -27,9 +27,13 @@ updates:
     labels:
       - "dependencies"
       - "pip"
+      - "v3"
   - package-ecosystem: "github-actions"
     directory: "/"
     schedule:
       interval: "weekly"
     target-branch: v3
+    labels:
+      - "github_actions"
+      - "v3"