Update ci.yml

Author: ctreffs

.github/workflows/ci.yml

@@ -16,6 +16,9 @@ jobs:
       - name: Checkout
         uses: actions/[email protected]
 
+      - name: Select Xcode ${{ matrix.xcode }}
+        run: sudo xcode-select -s /Applications/Xcode_${{ matrix.xcode }}.app
+        
       - name: Test
         run: swift test -v --skip-update --parallel --enable-code-coverage
         env: