different runs_on

Signed-off-by: Anas Nashif <[email protected]>

Author: nashif

.github/workflows/twister.yaml

@@ -22,11 +22,21 @@ concurrency:
 jobs:
   twister-build-prep:
     if: github.repository_owner == 'zephyrproject-rtos'
-    runs-on:
-      group: zephyr-runner-v2-linux-x64-4xlarge
+    runs-on: ${{ matrix.runs_on }}
+    strategy:
+      matrix:
+        event: [push]
+        include:
+          - event: push
+            runs_on: ubuntu-22.04
+          - event: pull_request_target
+            container_image: ghcr.io/zephyrproject-rtos/ci-repo-cache:v0.27.4.20241026
+            container_options: ""
+            runs_on:
+              group: zephyr-runner-v2-linux-x64-4xlarge
     container:
-      image: ghcr.io/zephyrproject-rtos/ci-repo-cache:v0.27.4.20241026
-      options: '--entrypoint /bin/bash'
+      image: ${{matrix.container_image}}
+      options: ${{matrix.container_options}}
     outputs:
       subset: ${{ steps.output-services.outputs.subset }}
       size: ${{ steps.output-services.outputs.size }}