Revert "CI: remove an old workaround in macOS CI"

This reverts commit b720c68.

Author: kdudka

.github/workflows/macos.yml

@@ -27,6 +27,12 @@ jobs:
 
       - name: Install dependencies
         run: |
+          # workaround for https://github.com/actions/setup-python/issues/577
+          for pkg in $(brew list | grep '^python@'); do
+            brew unlink "$pkg"
+            brew link --overwrite "$pkg"
+          done
+
           brew update
           brew install boost boost-python3 help2man