Revert "TEMP: Try python 3.8."

This reverts commit 8def4d5.

Author: moodyjon

.github/workflows/main.yml

@@ -10,7 +10,7 @@ jobs:
       - uses: actions/checkout@v3
       - uses: actions/setup-python@v4
         with:
-          python-version: '3.8'
+          python-version: '3.9'
       - name: extract pip cache
         uses: actions/cache@v3
         with:
@@ -34,7 +34,7 @@ jobs:
       - uses: actions/checkout@v3
       - uses: actions/setup-python@v4
         with:
-          python-version: '3.8'
+          python-version: '3.9'
       - name: set pip cache dir
         shell: bash
         run: echo "PIP_CACHE_DIR=$(pip cache dir)" >> $GITHUB_ENV
@@ -96,7 +96,7 @@ jobs:
       - uses: actions/checkout@v3
       - uses: actions/setup-python@v4
         with:
-          python-version: '3.8'
+          python-version: '3.9'
       - if: matrix.test == 'other'
         run: |
           sudo apt-get update
@@ -146,7 +146,7 @@ jobs:
       - uses: actions/checkout@v3
       - uses: actions/setup-python@v4
         with:
-          python-version: '3.8'
+          python-version: '3.9'
       - id: os-name
         uses: ASzc/change-string-case-action@v5
         with: