ci: improve the workaround for broken Python in macOS images

Related: https://github.com/actions/setup-python/issues/577

Author: lzaoral

.github/workflows/macos.yml

@@ -28,8 +28,10 @@ jobs:
       - name: Install dependencies
         run: |
           # workaround for https://github.com/actions/setup-python/issues/577
-          brew unlink python3
-          brew link --overwrite python3
+          for pkg in $(brew list | grep '^python@'); do
+            brew unlink "$pkg"
+            brew link --overwrite "$pkg"
+          done
 
           brew update
           brew install boost boost-python3 help2man