ci: remove tests from macos job on PRs

even when using the cache, the macos job on PR takes a lot of time, due
to the hardware limitations causing execution to take so much time. So
instead, we limit the macos job to the build to make sure it can
compile, and only run the tests for macos on push events

.github/workflows/continuous-integration.yml

@@ -173,24 +173,39 @@ jobs:
           key: ${{ runner.os }}-compilation-cache-${{ github.event.pull_request.base.sha }}
 
       - name: Get tmpdir path
+        if: github.event_name == 'push'
         id: tmpdir-path
         run: echo "::set-output name=TMPDIR_PATH::`echo $TMPDIR`"
 
       - name: KeySetCache
+        if: github.event_name == 'push'
         uses: actions/cache@v2
         with:
           path: ${{ steps.tmpdir-path.outputs.TMPDIR_PATH }}/KeySetCache
           key: ${{ runner.os }}-KeySetCache-2022-03-03-7pm
 
+      # We do run test-check as part of the build, as they aren't that costly
+      # and will at least give minimum confidence that the compiler works in PRs
       - name: Build
         run: |
           cd compiler
           echo "Debug: ccache statistics (prior to the build):"
           ccache -s
           export CONCRETE_PROJECT=${{ github.workspace }}/concrete
+          make python-bindings build-tests test-check
+          echo "Debug: ccache statistics (after the build):"
+          ccache -s
+
+      - name: Test
+        if: github.event_name == 'push'
+        run: |
+          cd compiler
+          echo "Debug: ccache statistics (prior to the tests):"
+          ccache -s
+          export CONCRETE_PROJECT=${{ github.workspace }}/concrete
           make install_runtime_lib
           make test
-          echo "Debug: ccache statistics (after the build):"
+          echo "Debug: ccache statistics (after the tests):"
           ccache -s
 
   BuildAndTestDF: