ci: reduce amount of data copied back from VM in FreeBSD action

By reducing the amount of data to be copied back from the VM to the host,
we hope that the chance on failure is reduced.

.github/workflows/vmactions.yml

@@ -56,6 +56,8 @@ jobs:
             -DSDL_CHECK_REQUIRED_LINK_OPTIONS="-L/usr/local/lib"
           cmake --build build/ --config Release --verbose -- -j`sysctl -n hw.ncpu`
           cmake --build build/ --config Release --target package
+          
+          cmake --build build/ --config Release --target clean
     - uses: actions/upload-artifact@v3
       with:
         if-no-files-found: error