CI: switch to ubuntu-latest

Author: mgerhardy

.github/workflows/main.yml

@@ -27,7 +27,7 @@ jobs:
             path: "build/caveexpress dev.dmg"
 
     linux:
-        runs-on: ubuntu-22.04
+        runs-on: ubuntu-latest
 
         steps:
         - uses: actions/checkout@v4