Add ubuntu-arm to CI.

Author: alexrp

.github/workflows/build.yml

@@ -26,7 +26,9 @@ jobs:
             - macos-15
             - ubuntu-20.04
             - ubuntu-22.04
+            - ubuntu-22.04-arm
             - ubuntu-24.04
+            - ubuntu-24.04-arm
             - windows-2019
             - windows-2022
             - windows-2025