add aarch64 to Ubuntu workflow (#1411)

Author: molpopgen

.github/workflows/ubuntu.yml

@@ -10,7 +10,7 @@ jobs:
     strategy:
       matrix:
         python: [ "3.10", "3.11", "3.12", "3.13" ]
-        os:  [ ubuntu-24.04 ]
+        os:  [ ubuntu-24.04, ubuntu-24.04-arm ]
         compiler: [gcc, clang14]
         rust: [1.62.1]
     defaults: