ci: fix syntax

Author: william-silversmith

.github/workflows/python-package.yml

@@ -11,11 +11,11 @@ on:
 
 jobs:
   build:
+    runs-on: ${{ matrix.os }}
     strategy:
       os: [ubuntu-latest, windows-latest]
       matrix:
         python-version: ["3.9", "3.10", "3.11", "3.12", "3.13"]
-    runs-on: ${{ matrix.os }}
 
     steps:
     - uses: actions/checkout@v2