ci: only run linting on Ubuntu (#5216)

Author: nschonni

.github/workflows/pull-request.yml

@@ -9,13 +9,8 @@ env:
 
 jobs:
   lint:
-    name: Lint on ${{ matrix.os }}
-    runs-on: ${{ matrix.os }}
-
-    strategy:
-      fail-fast: false
-      matrix:
-        os: [ubuntu-latest, windows-latest]
+    name: Lint
+    runs-on: ubuntu-latest
 
     steps:
       - name: Git Checkout