use macos-15 image

Author: zzzeid

.github/workflows/build.yml

@@ -122,14 +122,12 @@ jobs:
           coveralls --service=github
 
   build-and-test-mac-gui:
-    # macos-13 is the latest runner (as of time of writing) that does not cause a
-    # _tkinter import error during the build.
-    runs-on: macos-13
+    runs-on: macos-15
     env:
       # We need the official Python, because the GA ones only support newer macOS versions
       # The deployment target is picked up by the Python build tools automatically
-      PYTHON_VERSION: 3.12.4
-      MACOSX_DEPLOYMENT_TARGET: 10.13
+      PYTHON_VERSION: 3.13.9
+      MACOSX_DEPLOYMENT_TARGET: 10.15
       GITHUB_TOKEN: ${{ secrets.GITHUB_TOKEN }}
     steps:
       - uses: actions/checkout@v4
@@ -147,7 +145,7 @@ jobs:
         run: |
           source env/bin/activate
           python -m pip install --upgrade pip
-          python -m pip install -r requirements/requirements-3.12-macOS.txt
+          python -m pip install -r requirements/requirements-3.13-macOS.txt
           python -m pip install -e .
       - name: Build
         run: |