CI: Add software testing for Python 3.8 and 3.9

Author: amotl

.github/workflows/influxdb.yml

@@ -40,7 +40,11 @@ jobs:
         os: ["ubuntu-latest"]
         # TODO: yarl, dependency of influxio, is currently not available on Python 3.12.
         #       https://github.com/aio-libs/yarl/pull/942
-        python-version: ["3.8", "3.11"]
+        python-version: [
+          "3.8",
+          "3.9",
+          "3.11",
+        ]
         influxdb-version: ["2.6", "2.7"]
 
     env:

.github/workflows/main.yml

@@ -28,7 +28,11 @@ jobs:
       fail-fast: false
       matrix:
         os: ["ubuntu-latest"]
-        python-version: ["3.8", "3.12"]
+        python-version: [
+          "3.8",
+          "3.9",
+          "3.12",
+        ]
 
     env:
       OS: ${{ matrix.os }}

.github/workflows/mongodb.yml

@@ -38,7 +38,11 @@ jobs:
       fail-fast: false
       matrix:
         os: ["ubuntu-latest"]
-        python-version: ["3.8", "3.11"]
+        python-version: [
+          "3.8",
+          "3.9",
+          "3.11",
+        ]
         mongodb-version: ["3", "4", "5", "6", "7"]
 
     env: