Print used swift version (useful for nightly)

Author: ktoso

.github/actions/prepare_env/action.yml

@@ -4,6 +4,9 @@ description: 'Prepare the CI environment by installing Swift and selected JDK et
 runs:
   using: composite
   steps:
+    - name: Check Swift version
+      shell: bash
+      run: swift -version
     - name: Set up JDK ${{ matrix.jdk_version }}
       uses: actions/setup-java@v4
       with: