fix typo

Author: codehz

.github/workflows/test.yaml

@@ -16,7 +16,7 @@ jobs:
           - ubuntu-latest
           - windows-latest
           - macOS-latest
-    run-on: ${{ matrix.os }}
+    runs-on: ${{ matrix.os }}
     steps:
       - uses: actions/checkout@v2
       - uses: jiro4989/setup-nim-action@v1