Adjust actions

.github/workflows/build.yml

@@ -11,15 +11,12 @@ concurrency:
   cancel-in-progress: true
 
 env:
-  RUNTIME_VERSION: 17
+  RUNTIME_VERSION: 21
 
 jobs:
   build:
     # Only run on PRs if the source branch is on someone else's repo
     if: "${{ github.event_name != 'pull_request' || github.repository != github.event.pull_request.head.repo.full_name }}"
-    strategy:
-      matrix:
-        os: ["ubuntu-latest", "windows-latest"]
     runs-on: "${{ matrix.os }}"
     steps:
       - name: "checkout repository"