ci: use ubuntu-24.04

Replace ubuntu-latest with ubuntu-24.04 to pre-empt this future change.

Author: JakeOShannessy

.github/workflows/cmake.yml

@@ -33,7 +33,7 @@ permissions:
 jobs:
   cmake-linux:
     name: ${{ matrix.container }} ${{ matrix.compiler_mpi }} openmp=${{ matrix.openmp }} ${{ matrix.build_type }}
-    runs-on: [ubuntu-latest]
+    runs-on: [ubuntu-24.04]
     container: ${{ matrix.container }}
     strategy:
       matrix: