Fixes #10590

Implement missing safeguard causing `gh alias delete` tests to wipe out tester's GitHub CLI configuration.

pkg/cmd/alias/delete/delete_test.go

@@ -162,6 +162,9 @@ func TestDeleteRun(t *testing.T) {
 			tt.opts.IO = ios
 
 			cfg := config.NewFromString(tt.config)
+			cfg.WriteFunc = func() error {
+				return nil
+			}
 			tt.opts.Config = func() (gh.Config, error) {
 				return cfg, nil
 			}