Use 16 core cncf runners to build k3s

Add actionlint exception for CNCF runner names
Signed-off-by: Derek Nola <derek.nola@suse.com>

.github/actionlint.yaml

@@ -0,0 +1,3 @@
+self-hosted-runner:
+  labels:
+    - cncf-ubuntu-*

.github/workflows/build-k3s.yaml

@@ -26,7 +26,7 @@ permissions:
 jobs:
   build:
     name: Build # DO NOT CHANGE THIS NAME, we rely on it for INSTALL_K3S_PR functionality
-    runs-on: ${{ contains(inputs.arch, 'arm') && 'ubuntu-24.04-arm' || 'ubuntu-24.04' }}
+    runs-on: ${{ contains(inputs.arch, 'arm') && (github.repository_owner == 'k3s-io' && 'cncf-ubuntu-16-64-arm' || 'ubuntu-24.04-arm') || (github.repository_owner == 'k3s-io' && inputs.arch == 'amd64' && 'cncf-ubuntu-16-64-x86' || 'ubuntu-24.04') }}
     timeout-minutes: 20
     env:
       BIN_EXT: ${{ inputs.os == 'windows' && '.exe' || '' }}

.github/workflows/e2e.yaml

@@ -11,6 +11,7 @@ on:
       - ".github/**"
       - "!.github/actions/**"
       - "!.github/workflows/e2e.yaml"
+      - "!.github/workflows/build-k3s.yaml"
   pull_request:
     paths-ignore:
       - "**.md"

.github/workflows/integration.yaml

@@ -9,6 +9,7 @@ on:
       - "!tests/integration**"
       - ".github/**"
       - "!.github/workflows/integration.yaml"
+      - "!.github/workflows/build-k3s.yaml"
   pull_request:
     paths-ignore:
       - "**.md"