CI: Remove MacOS 13 acceptance tests

The MacOS 13 runners are deprecated and got removed:

actions/runner-images#13046

Author: bastelfreak

.github/workflows/acceptance_tests.yml

@@ -22,7 +22,6 @@ jobs:
           - windows-2022
           - ubuntu-22.04
           - ubuntu-24.04
-          - macos-13
       fail-fast: false
     runs-on: ${{ matrix.os }}
     env: