Ensure Dependabot PR workflow retriggers on label change (#269)

Solves a race condition when PR is created but not yet labeled.

Signed-off-by: Thomas Farr <tsfarr@amazon.com>

Signed-off-by: Thomas Farr <tsfarr@amazon.com>

.github/workflows/dependabot_pr.yml

@@ -1,5 +1,12 @@
 name: Dependabot PR actions
-on: pull_request
+on: 
+  pull_request:
+    types:
+      - opened
+      - reopened
+      - synchronize
+      - labeled
+      - unlabeled
 
 jobs:
   dependabot:
@@ -18,12 +25,12 @@ jobs:
           installation_id: 22958780
 
       - name: Check out code
-        uses: actions/checkout@v2
+        uses: actions/checkout@v3
         with:
           token: ${{ steps.github_app_token.outputs.token }}
 
       - name: Update the changelog
-        uses: dangoslen/dependabot-changelog-helper@v1
+        uses: dangoslen/dependabot-changelog-helper@v2
         with:
           version: 'Unreleased'