Avoid running semgrep on merge groups (#4)

Semgrep is taking an awful amount of time when running in merge queues, this is disabling it for those cases while keeping the workflow running to fit the requirement.

.github/workflows/semgrep.yml

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