ci: prevent jobs running on PRs from forks

Signed-off-by: Mohammed Al Sahaf <[email protected]>

.github/workflows/ci.yml

@@ -143,7 +143,7 @@ jobs:
   s390x-test:
     name: test (s390x on IBM Z)
     runs-on: ubuntu-latest
-    if: github.event.pull_request.head.repo.full_name == github.repository && github.actor != 'dependabot[bot]'
+    if: (github.repository == 'caddyserver/caddy' && github.event_name != 'pull_request') || (github.event_name == 'pull_request' && github.event.pull_request.head.repo.full_name == 'caddyserver/caddy') && github.actor != 'dependabot[bot]'
     continue-on-error: true  # August 2020: s390x VM is down due to weather and power issues
     steps:
       - name: Checkout code
@@ -194,7 +194,7 @@ jobs:
 
   goreleaser-check:
     runs-on: ubuntu-latest
-    if: github.repository_owner == 'caddyserver' && github.actor != 'dependabot[bot]'
+    if: (github.repository == 'caddyserver/caddy' && github.event_name != 'pull_request') || (github.event_name == 'pull_request' && github.event.pull_request.head.repo.full_name == 'caddyserver/caddy') && github.actor != 'dependabot[bot]'
     steps:
       - name: Checkout code
         uses: actions/checkout@v4