MacOS runner: install GNU coreutils

Author: Vectorial1024

.github/workflows/macos_l11.yml

@@ -25,6 +25,9 @@ jobs:
       with:
         php-version: '8.2'
 
+    - name: "Homebrew: Install GNU Core Utilities"
+      run: yes | sudo brew install coreutils
+
     - name: Validate composer.json and composer.lock
       run: composer validate --strict