ci: Test against Windows

Fx supports Windows and has tests against it.
Therefore, Dig needs to test against Windows as well
to catch any potential issues before release.

.github/workflows/go.yml

@@ -13,10 +13,11 @@ permissions:
 jobs:
 
   build:
-    runs-on: ubuntu-latest
-    name: Test (Go ${{ matrix.go }})
+    runs-on: ${{ matrix.os }}
+    name: Test (Go ${{ matrix.go }} / ${{ matrix.os }})
     strategy:
       matrix:
+        os: ["ubuntu-latest", "windows-latest"]
         go: ["1.20.x", "1.21.x"]
 
     steps: