fix: matrix

Author: conblem

.github/workflows/rust.yaml

@@ -63,7 +63,7 @@ jobs:
     runs-on: ${{ matrix.os }}
     strategy:
       matrix:
-        os: [ macos-latest, windows-latest, ubuntu-latest ],
+        os: [ macos-latest, windows-latest, ubuntu-latest ]
         toolchain: [ stable, nightly ]
     steps:
       - uses: actions/checkout@v2