Test on macOS 26

Author: cclauss

.github/workflows/tox.yml

@@ -13,10 +13,14 @@ on:
 
 jobs:
   tests:
-    runs-on: macos-latest
     strategy:
       matrix:
+        os: [ macos-latest ]
         python-version: [ '3.10', '3.11', '3.12', '3.13' ]
+        include:
+          - os: macos-26
+            python-version: 3.x
+    runs-on: ${{ matrix.os }}
     steps:
       - uses: actions/checkout@v4
       - name: Set up Python V${{ matrix.python-version }}