Fix the problem that colorDirty of bmfont on web platform doesn't wor…

…k. (#17037)

Co-authored-by: qiuguohua <guohua.qiu@cocos.com>

cocos/2d/assembler/label/bmfontUtils.ts

@@ -143,7 +143,7 @@ export const bmfontUtils = {
             // But this function is not called when just modifying the opacity.
             // So the value of '_comp.node._uiProps.colorDirty' does not change.
             // And _uiProps.colorDirty is synchronized with renderEntity.colorDirty.
-            if (_comp.renderEntity.colorDirty || isResized) {
+            if (JSB && (_comp.renderEntity.colorDirty || isResized)) {
                 this.updateColor(comp); // dirty need
                 _comp.node._uiProps.colorDirty = false;
             }