build: Add SGX, VFIO and rate limit testing to MQ

Run these workflows as part of the merge queue to help improve testing
coverage.

Signed-off-by: Rob Bradford <rbradford@rivosinc.com>
(cherry picked from commit cdafe5344d)

.github/workflows/integration-rate-limiter.yaml

@@ -1,21 +1,23 @@
 name: Cloud Hypervisor Tests (Rate-Limiter)
-on:
-  push:
-    branches:
-      - main
+on: [merge_group, pull_request]
 
 jobs:
   build:
     name: Tests (Rate-Limiter)
-    runs-on: jammy-rate-limiter
+    runs-on: ${{ github.event_name == 'pull_request' && 'ubuntu-latest' || 'jammy-rate-limiter' }}
     steps:
       - name: Fix workspace permissions
         if: ${{ github.event_name != 'pull_request' }}
         run: sudo chown -R github-runner:github-runner ${GITHUB_WORKSPACE}
       - name: Code checkout
+        if: ${{ github.event_name != 'pull_request' }}
         uses: actions/checkout@v4
         with:
           fetch-depth: 0
       - name: Run rate-limiter integration tests
+        if: ${{ github.event_name != 'pull_request' }}
         timeout-minutes: 10
         run: scripts/dev_cli.sh tests --integration-rate-limiter
+      - name: Skipping build for PR
+        if: ${{ github.event_name == 'pull_request' }}
+        run: echo "Skipping build for PR"