Excluded pypy+macOS 11 from the test matrix

Github Actions does not provide these interpreters on macOS 11 yet.

Author: agronholm

.github/workflows/codeqa-test.yml

@@ -23,9 +23,9 @@ jobs:
         os: [ubuntu-latest, macos-10.15, macos-11.0, windows-latest]
         python-version: [2.7, 3.6, 3.9, pypy2, pypy3]
         exclude:
-        - os: macos-latest
+        - os: macos-11.0
           python-version: pypy2
-        - os: macos-latest
+        - os: macos-11.0
           python-version: pypy3
         - os: windows-latest
           python-version: 2.7