CI: Unit tests: Run on Ubuntu 24.04

Author: bastelfreak

.github/workflows/unit.yaml

@@ -1,3 +1,4 @@
+---
 name: Unit tests
 
 on:
@@ -23,7 +24,7 @@ jobs:
     name: Unit
     strategy:
       matrix:
-        os: [ubuntu-22.04, windows-latest]
+        os: [ubuntu-24.04, windows-latest]
         ruby: [3.1]
     runs-on: ${{ matrix.os }}
     steps: