(DO NOT MERGE) Does this now work in aarch64-gnu?

Author: Zalathar

src/ci/github-actions/jobs.yml

@@ -102,6 +102,8 @@ pr:
     <<: *job-linux-16c
   - image: x86_64-gnu-tools
     <<: *job-linux-16c
+  - image: aarch64-gnu
+    <<: *job-aarch64-linux
 
 # Jobs that run when you perform a try build (@bors try)
 # These jobs automatically inherit envs.try, to avoid repeating