GitHub macOS build with homebrew clean slate

git-svn-id: https://svn.code.sf.net/p/vice-emu/code/trunk@45846 379a1393-f5fb-40a0-bcee-ef074d9b53f7

Author: dqh-au

.github/workflows/build-main-on-push.yml

@@ -558,6 +558,7 @@ jobs:
         run: |
           export HOMEBREW_NO_INSTALL_CLEANUP=1
           brew update
+          brew list -1 | xargs brew uninstall --force
           brew install ${{ env.SHARED_DEPS }} ${{ matrix.ui.deps }}
       
       - name: Build