Added Windows to CI

Author: ankane

.github/workflows/build.yml

@@ -2,15 +2,13 @@ name: build
 on: [push, pull_request]
 jobs:
   build:
-    runs-on: ubuntu-latest
+    runs-on: windows-latest
     strategy:
       fail-fast: false
       matrix:
         include:
           - ruby: 3.4
-            postgres: 18
-          - ruby: 2.7
-            postgres: 9.6
+            postgres: 17
     steps:
       - uses: actions/checkout@v5
       - uses: ruby/setup-ruby@v1