UnitTesting: generate matrix of jobs dynamically

.github/workflows/UnitTesting.yml

@@ -3,6 +3,11 @@ name: Unit Testing
 on:
   workflow_call:
     inputs:
+      python_versions:
+        description: 'Space separated list of Python versions to run tests with.'
+        required: false
+        default: '3.6 3.7 3.8 3.9 3.10'
+        type: string
       requirements:
         description: 'Python dependencies to be installed through pip.'
         required: false
@@ -16,19 +21,40 @@ on:
 
 jobs:
 
+
+  Versions:
+    runs-on: ubuntu-latest
+    outputs:
+      jobs: ${{ steps.versions.outputs.jobs }}
+    steps:
+
+      - id: versions
+        shell: python
+        run: |
+          icons = {
+             '3.6': '🔴', # until 23.12.2021
+             '3.7': '🟠', # until 27.06.2023
+             '3.8': '🟡', # until Oct. 2024
+             '3.9': '🟢', # until Oct. 2025
+            '3.10': '🟢', # until Oct. 2026
+          }
+          jobs = [
+              {'python': version, 'icon': icons[version]}
+              for version in '${{ inputs.python_versions }}'.split(' ')
+          ]
+          print(f'::set-output name=jobs::{jobs!s}')
+
+
   UnitTesting:
     name: ${{ matrix.icon }} Unit Tests using Python ${{ matrix.python }}
     runs-on: ubuntu-latest
+    needs:
+      - Versions
 
     strategy:
       fail-fast: false
       matrix:
-        include:
+        include: ${{ fromJson(needs.Versions.outputs.jobs) }}
-#          - {python: "3.6",  icon: 🔴} # until 23.12.2021
-          - {python: "3.7",  icon: 🟠} # until 27.06.2023
-          - {python: "3.8",  icon: 🟡} # until Oct. 2024
-          - {python: "3.9",  icon: 🟢} # until Oct. 2025
-          - {python: "3.10", icon: 🟢} # until Oct. 2026
 
     steps:
       - name: ⏬ Checkout repository