Run test-fast job (also) on Linux arm64 preview runner

https://github.blog/changelog/2025-01-16-linux-arm64-hosted-runners-now-available-for-free-in-public-repositories-public-preview/

Author: EliahKagan

.github/workflows/ci.yml

@@ -135,6 +135,7 @@ jobs:
           - windows-latest
           - macos-latest
           - ubuntu-latest
+          - ubuntu-24.04-arm
 
     runs-on: ${{ matrix.os }}