Remove any references to Python 3.8

Author: DimitriPapadopoulos

.github/workflows/main.yaml

@@ -32,7 +32,7 @@ jobs:
       - name: Setup conda
         uses: conda-incubator/setup-miniconda@v3
         with:
-          environment-file: ci/environment-py38.yml
+          environment-file: ci/environment-py39.yml
           python-version: ${{ matrix.PY }}
 
       - name: Run Tests

ci/environment-py38.yml renamed to ci/environment-py39.yml

@@ -4,7 +4,7 @@ channels:
 dependencies:
   - mypy=1.4.1
   - pyarrow
-  - python=3.8
+  - python=3.9
   - pip
   - pip:
     - types-paramiko