(chore) CI: drop support for eol Python versions

Author: kbdharun

.github/workflows/publish.yml

@@ -18,7 +18,7 @@ jobs:
     - name: Set up Python
       uses: actions/setup-python@v4
       with:
-        python-version: '3.7'
+        python-version: '3.8'
 
     - name: Install sphinx toolset
       run: >-

.github/workflows/test.yml

@@ -8,7 +8,7 @@ jobs:
 
     strategy:
       matrix:
-        python-version: ['3.6', '3.7', '3.8', '3.9', '3.10', '3.11', 'pypy3.9']
+        python-version: ['3.8', '3.9', '3.10', '3.11', 'pypy3.9']
 
     steps:
     - uses: actions/checkout@v3