Merge branch 'main' into rob/413-ttc-not-using-nonstandardcodeinstance

Author: robertandremitchell

.github/workflows/check_unit_tests.yml

@@ -39,7 +39,7 @@ jobs:
           uv run coverage xml -o coverage.xml
 
       - name: Upload combined coverage to Codecov
-        uses: codecov/codecov-action@v5
+        uses: codecov/codecov-action@v6
         with:
           token: ${{ secrets.CODECOV_TOKEN }}
           files: coverage.xml