github: workflows: Use ubuntu 24.04 for testbench

The ubuntu LTS releases have far more runners than more recent non LTS
releases. Use the LTS to avoid runner timeouts.

Signed-off-by: Liam Girdwood <liam.r.girdwood@linux.intel.com>

Author: lrgirdwo

.github/workflows/testbench.yml

@@ -30,7 +30,7 @@ on:
 
 jobs:
   build-and-test:
-    runs-on: ubuntu-24.10
+    runs-on: ubuntu-24.04
 
     steps:
       - name: Checkout SOF repository (PR source)