Fix APK builder test database cleanup on Windows.

Close the SQLite handle before temp dir teardown so TestBuildAPKAgentMockGradle passes reliably on Windows CI.

server/internal/builder/build_apk_test.go

@@ -39,7 +39,8 @@ func TestPlatformsForRequestApkMode(t *testing.T) {
 }
 
 func TestBuildAPKAgentMockGradle(t *testing.T) {
-	h, _ := testHandlerDB(t)
+	h, database := testHandlerDB(t)
+	t.Cleanup(func() { _ = database.Close() })
 	setFakeGoSuccess(t, h)
 
 	androidDir := filepath.Join(h.projectRoot, "android")