Update semgrep.yml (#7)

After chatting with Semgrep support, determined that the reason this action hangs for github actions that check the results of `terraform fmt` into a PR is because it should be excluded anyway.

.github/workflows/semgrep.yml

@@ -24,7 +24,7 @@ jobs:
       credentials:
         username: ${{ github.actor }}
         password: ${{ secrets.github_token }}
-    if: github.actor != 'dependabot[bot]' && github.event_name != 'merge_group'
+    if: github.actor != 'dependabot[bot]' && github.actor != 'github-actions' && github.event_name != 'merge_group'
     steps:
       - uses: actions/checkout@v4
       - name: Run semgrep ci