CI-unixish.yml: removed installation of python3 as it is already part of the image

Author: firewave

.github/workflows/CI-unixish.yml

@@ -47,11 +47,6 @@ jobs:
       run: |
         brew install coreutils
 
-    - name: Install missing software on macos
-      if: contains(matrix.os, 'macos')
-      run: |
-        brew install python3
-
     - name: Install missing Python packages
       run: |
         python3 -m pip config set global.break-system-packages true