ci: Update macos runner images

macos-13 is deprecated

Author: ales-erjavec

.github/workflows/run-tests-workflow.yml

@@ -49,19 +49,19 @@ jobs:
             extra-system-packages: "glibc-tools"
 
           # macOS
-          - os: macos-12
+          - os: macos-13
             python-version: 3.9
             test-env: "PyQt5~=5.14.0"
 
-          - os: macos-12
+          - os: macos-13
             python-version: "3.10"
             test-env: "PyQt5~=5.15.0"
 
-          - os: macos-13
+          - os: macos-14
             python-version: "3.11"
             test-env: "PyQt5~=5.15.0"
 
-          - os: macos-14
+          - os: macos-15
             python-version: "3.11"
             test-env: "PyQt6~=6.2.3 PyQt6-Qt6~=6.2.3"