CI: remove Python 3.5 (end of life)

Author: mgeier

.github/workflows/python-versions.yml

@@ -4,7 +4,7 @@ jobs:
   python:
     strategy:
       matrix:
-        python-version: ["3.5", "3.6", "3.7", "3.8", "3.9", pypy3]
+        python-version: ["3.6", "3.7", "3.8", "3.9", pypy3]
     runs-on: ubuntu-latest
     steps:
       - name: Install PortAudio