fixup

Author: guybedford

.github/workflows/pullrequest.yml

@@ -199,9 +199,11 @@ jobs:
         run: chomp test:unit
 
       - name: Set up Docker Buildx
+        if: matrix.platform == 'ubuntu-latest'
         uses: docker/setup-buildx-action@v3
 
       - name: Build Container
+        if: matrix.platform == 'ubuntu-latest'
         uses: docker/build-push-action@v6
         with:
           context: ./test/container-echo
@@ -213,7 +215,7 @@ jobs:
 
       - name: Run tests
         env:
-          TEST_CONTAINER_NAME: worker-dev/echocontainer:latest
+          TEST_CONTAINER_NAME: ${{ matrix.platform == 'ubuntu-latest' && 'worker-dev/echocontainer:latest' || '' }
         run: chomp test
 
       - name: Run tests (http)