CI: Select latest Xcode

Author: freak4pc

.github/workflows/tests.yml

@@ -25,8 +25,6 @@ jobs:
 
     steps:
       - uses: actions/checkout@v2
-      - name: Select Xcode 12 (beta)
-        run: sudo xcode-select -s /Applications/Xcode_12_beta.app
       - name: Generate project
         run: make project
       - name: Run tests