(build) Update GHA to pin ubuntu version

Author: corbob

.github/workflows/build.yml

@@ -11,7 +11,7 @@ on:
 jobs:
   # Build using mono on Ubuntu
   ubuntu-build:
-    runs-on: ubuntu-latest
+    runs-on: ubuntu-22.04
     steps:
     - uses: actions/checkout@v3
       with: