CI (GHA, Buildbot): temporarily, don't create the linuxaarch64 Buildbot status (JuliaLang#42954)

Author: DilumAluthge

.github/workflows/statuses.yml

@@ -50,7 +50,7 @@ jobs:
                 "buildbot/tester_freebsd64"
                 "buildbot/tester_linux32"
                 "buildbot/tester_linux64"
-                "buildbot/tester_linuxaarch64"
+                # "buildbot/tester_linuxaarch64" # TODO: uncomment this line
                 "buildbot/tester_macos64"
                 "buildbot/tester_win32"
                 "buildbot/tester_win64"