(actions) update matrix to include U24, drop U20 (#480)

Author: MatthijsBurgh

.github/workflows/main.yml

@@ -12,29 +12,20 @@ jobs:
     strategy:
       fail-fast: false
       matrix:
-        os: [ubuntu-20.04, ubuntu-22.04]
+        os: [ubuntu-22.04, ubuntu-24.04]
         orocos_build_type: [Debug, Release]
         compiler: [gcc, clang]
-        python_version: ['3.8', '3.10']
-        exclude:
-          - os: ubuntu-20.04
-            python_version: '3.10'
-          - os: ubuntu-22.04
-            python_version: '3.8'
+        python_version: ['3.10', '3.12']
         include:
-          - os: ubuntu-20.04
-            orocos_build_type: Release
-            compiler: gcc
-            python_version: '3.9'
-          - os: ubuntu-20.04
+          - os: ubuntu-24.04
             orocos_build_type: Release
             compiler: gcc
-            python_version: '3.10'
-          - os: ubuntu-20.04
+            python_version: '3.8'
+          - os: ubuntu-24.04
             orocos_build_type: Release
             compiler: gcc
-            python_version: '3.11'
-          - os: ubuntu-22.04
+            python_version: '3.9'
+          - os: ubuntu-24.04
             orocos_build_type: Release
             compiler: gcc
             python_version: '3.11'