Use CNCF 8 core runner if available

Signed-off-by: Derek Nola <derek.nola@suse.com>

Author: dereknola

.github/workflows/pr.yaml

@@ -10,7 +10,7 @@ permissions:
 
 jobs:
   build:
-    runs-on: ubuntu-latest
+    runs-on: ${{ github.repository_owner == 'k3s-io' && 'cncf-ubuntu-8-32-x86' || 'ubuntu-latest' }}
 
     steps:
       - name: Set up QEMU

.github/workflows/release.yml

@@ -10,7 +10,7 @@ env:
 
 jobs:
   build-and-push:
-    runs-on: ubuntu-latest
+    runs-on: ${{ github.repository_owner == 'k3s-io' && 'cncf-ubuntu-8-32-x86' || 'ubuntu-latest' }}
 
     permissions:
       contents: read