use correct arch

Author: qui-jason

.github/workflows/dargon2_flutter_tests.yml

@@ -64,7 +64,7 @@ jobs:
         with:
           api-level: 33
           target: google_apis
-          arch: arm-v8a
+          arch: arm64-v8a
           working-directory: dargon2_flutter/dargon2_flutter/example
           script: flutter test integration_test/