ci: downgrade Keepkey sim builder to Ubuntu 22.04

Author: Sjors

.github/workflows/ci.yml

@@ -216,7 +216,7 @@ jobs:
 
   sim-builder-keepkey:
     name: Keepkey sim builder
-    runs-on: ubuntu-latest
+    runs-on: ubuntu-22.04
 
     strategy:
       fail-fast: false