Try updated runner image to fix valgrind problem

Author: Hendrik van Antwerpen

.github/workflows/ci.yml

@@ -13,7 +13,9 @@ concurrency:
 
 jobs:
   test-rust:
-    runs-on: ubuntu-latest
+    # We force a newer runner version to fix a problem with Valgrind.
+    # Currently, ubuntu-latest is set to 22.04. Revert this back to ubuntu-latest once it is set to 24.04.
+    runs-on: ubuntu-24.04
     strategy:
       matrix:
         rust: [stable]