Swift: turn on macOS QL tests with slicing

.github/workflows/swift.yml

@@ -72,9 +72,15 @@ jobs:
   qltests-macos:
     needs: build-macos
     runs-on: macos-12-xl
+    strategy:
+      fail-fast: false
+      matrix:
+        slice: ["1/2", "2/2"]
     steps:
       - uses: actions/checkout@v3
       - uses: ./swift/actions/run-ql-tests
+        with:
+          flags: --slice ${{ matrix.slice }}
   integration-tests-linux:
     needs: build-linux
     runs-on: ubuntu-latest

swift/actions/run-ql-tests/action.yml

@@ -1,5 +1,10 @@
 name: Build Swift CodeQL pack
 description: Builds the Swift CodeQL pack
+inputs:
+  flags:
+    description: "Additional `codeql test run` flags"
+    required: false
+    default: ""
 runs:
   using: composite
   steps:
@@ -23,6 +28,7 @@ runs:
           --check-repeated-labels \
           --check-redefined-labels \
           --check-use-before-definition \
+          ${{ inputs.flags }} \
           ql/test
       env:
         GITHUB_TOKEN: ${{ github.token }}