[bfops/migrate-ci]: simplify names?

Author: bfops

.github/workflows/ci.yml

@@ -320,6 +320,7 @@ jobs:
     name: Test spacetimedb-update flow
     permissions: read-all
     strategy:
+      target: [x86_64-unknown-linux-gnu, aarch64-unknown-linux-gnu, aarch64-apple-darwin, x86_64-pc-windows-msvc]
       matrix:
         include:
           - runner: spacetimedb-new-runner