fix: Changes on pull_request -> pull_request_target (#603)

* changes `on` pull_request -> pull_request_target

An attempt to make this workflow approve and merge as expected.

* Adds a step to rebase if PR `mergeable_state` is `behind`

Author: willum070

.github/workflows/dependabot.yml

@@ -13,7 +13,7 @@
 # limitations under the License.
 
 name: Dependabot
-on: pull_request
+on: pull_request_target
 
 permissions:
   contents: write
@@ -27,8 +27,10 @@ jobs:
       PR_URL: ${{ github.event.pull_request.html_url }}
       GH_TOKEN: ${{ secrets.GITHUB_TOKEN }}
     steps:
+      - name: Rebase if behind
+        if: github.event.pull_request.mergeable_state == 'behind'
+        run: gh pr comment --body "@dependabot rebase" "$PR_URL"
       - name: approve
         run: gh pr review --approve "$PR_URL"
       - name: merge
         run: gh pr merge --auto --squash --delete-branch "$PR_URL"
-