Run Windows, Mac and coverage jobs on upper-bound Py3.13 not 3.12

Author: CAM-Gerlach

.github/workflows/tests.yaml

@@ -50,7 +50,7 @@ jobs:
             - QT_LIB: 'pyqt6'
               QT_DEPS: 'pyqt6!=6.4.0 pyqt6-qt6!=6.4.0'
             - RUNNER_OS: 'ubuntu'
-              PYTHON_VERSION: '3.12'
+              PYTHON_VERSION: '3.13'
               COVERAGE: 'True'
               COVERAGE_DEPS: 'coveralls pytest-cov'
               PYTEST_COVERAGE_ARGS: '--cov=qtconsole'
@@ -64,7 +64,7 @@ jobs:
           - RUNNER_OS: 'windows'
             PYTHON_VERSION: '3.11'
           - RUNNER_OS: 'windows'
-            PYTHON_VERSION: '3.13'
+            PYTHON_VERSION: '3.12'
           - RUNNER_OS: 'windows'
             INSTALL_TYPE: 'pip'
           - RUNNER_OS: 'windows'
@@ -74,7 +74,7 @@ jobs:
           - RUNNER_OS: 'macos'
             PYTHON_VERSION: '3.11'
           - RUNNER_OS: 'macos'
-            PYTHON_VERSION: '3.13'
+            PYTHON_VERSION: '3.12'
           - RUNNER_OS: 'macos'
             INSTALL_TYPE: 'pip'
           - RUNNER_OS: 'macos'