chore: expand testing platforms

Author: ilotoki0804

.github/workflows/testing.yaml

@@ -10,8 +10,8 @@ jobs:
   testing:
     strategy:
       matrix:
-        os: [ubuntu-latest]
-        python-version: ['3.10', '3.11', '3.12', '3.13', '3.14-dev']
+        os: [ubuntu-latest, windows-latest, macos-latest]
+        python-version: ['3.10', '3.11', '3.12', '3.13', '3.14']
 
     runs-on: ${{ matrix.os }}
     steps: