Update check jobs

Moving to actions/checkout v4 to clean warning message due to [1].
We also add coverage of py3.12, and remove py3.7 and 3.8 coverage.

[1] https://github.blog/changelog/2023-09-22-github-actions-transitioning-from-node-16-to-node-20/

.github/workflows/test.yml

@@ -8,9 +8,9 @@ jobs:
       runs-on: ubuntu-latest
       strategy:
         matrix:
-          python: ['3.7', '3.8', '3.9', '3.10', '3.11']
+          python: ['3.9', '3.10', '3.11', '3.12']
       steps:
-        - uses: actions/checkout@v3
+        - uses: actions/checkout@v4
         - name: Setup Python
           uses: actions/setup-python@v4
           with:
@@ -24,11 +24,11 @@ jobs:
     flake8:
       runs-on: ubuntu-latest
       steps:
-        - uses: actions/checkout@v3
+        - uses: actions/checkout@v4
         - name: Setup Python
           uses: actions/setup-python@v4
           with:
-            python-version: 3.11
+            python-version: 3.12
         - name: Install Tox and any other packages
           run: |
             python -m pip install --upgrade pip
@@ -38,11 +38,11 @@ jobs:
     integration:
       runs-on: ubuntu-latest
       steps:
-        - uses: actions/checkout@v3
+        - uses: actions/checkout@v4
         - name: Setup Python
           uses: actions/setup-python@v4
           with:
-            python-version: 3.11
+            python-version: 3.12
         - name: Install Tox and any other packages
           run: |
             python -m pip install --upgrade pip

tox.ini

@@ -1,6 +1,6 @@
 [tox]
 envlist = 
-    py{37,38,39,310,311}
+    py{39,310,311,312}
     flake8
 
 [testenv]