CI: bump macos

Github dropped macos-11, introduced 13 and 14

.github/workflows/tests.yml

@@ -8,8 +8,8 @@ jobs:
         os:
           - ubuntu-22.04
           - ubuntu-20.04
-          - macos-12
-          - macos-11
+          - macos-14
+          - macos-13
     runs-on: ${{ matrix.os }}
     steps:
       - uses: actions/checkout@v2