refactor(util): reorder gemini schema cleaner helpers

internal/runtime/executor/antigravity_executor.go

@@ -1213,7 +1213,6 @@ func (e *AntigravityExecutor) buildRequest(ctx context.Context, auth *cliproxyau
 		// Use the centralized schema cleaner to handle unsupported keywords,
 		// const->enum conversion, and flattening of types/anyOf.
 		strJSON = util.CleanJSONSchemaForAntigravity(strJSON)
-
 		payload = []byte(strJSON)
 	} else {
 		strJSON := string(payload)