[Docs Site] Update semgrep workflow (#17000)

* Update semgrep.yml

* Update semgrep.yml

Author: hrushikeshdeshpande

.github/workflows/semgrep.yml

@@ -12,14 +12,14 @@ name: Semgrep config
 jobs:
   semgrep:
     name: semgrep/ci
-    runs-on: ubuntu-20.04
+    runs-on: ubuntu-latest
     env:
       SEMGREP_APP_TOKEN: ${{ secrets.SEMGREP_APP_TOKEN }}
       SEMGREP_URL: https://cloudflare.semgrep.dev
       SEMGREP_APP_URL: https://cloudflare.semgrep.dev
       SEMGREP_VERSION_CHECK_URL: https://cloudflare.semgrep.dev/api/check-version
     container:
-      image: returntocorp/semgrep
+      image: semgrep/semgrep
     steps:
-      - uses: actions/checkout@v3
+      - uses: actions/checkout@v4
       - run: semgrep ci