Remove okButtonDisabled/cancelButtonDisabled never used prop defs

- Also remove them from the CHANGELOG because they were never actually
implemented, the prop was renamed to okButtonProps/cancelButtonProps
within PR #10955 but these prop defs were left behind and ended up
incorrectly included in the CHANGELOG.

CHANGELOG.en-US.md

@@ -1223,7 +1223,6 @@ Component Fixes / Enhancements:
 - 🐞 Cascader adds `fieldNames` and discards the misspelled `filedNames`. [#10896](https://github.com/ant-design/ant-design/issues/10896)
 - 🐞 Fix Timeline dot not working with Tooltip. [0e3b67e](https://github.com/ant-design/ant-design/commit/0e3b67e9999d867cc304f3be61a8a042a2ab92ee)
 - 🐞 Fix border radius when avatar has custom size. [e1e6523](https://github.com/ant-design/ant-design/commit/e1e6523452286ba56f20b73abad762a58ea7d7bc)
-- 🌟 Add `okButtonDisabled` and `cancelButtonDisabled` props to disable ok button and cancel button. [#10955](https://github.com/ant-design/ant-design/pull/10955)
 
 ## 3.6.6
 

CHANGELOG.zh-CN.md

@@ -1222,7 +1222,6 @@ timeline: true
 - Tree 组件升级 `rc-tree` 到 `1.12.0`
   - 🌟 新增 `loadedKeys` 属性，用于设置已经加载的节点，需要配合 `loadData` 使用。[#10666](https://github.com/ant-design/ant-design/issues/10666)
   - 🌟 新增 `onLoad` 属性，作为节点加载完毕时的回调函数。[c488aca](https://github.com/ant-design/ant-design/commit/c488aca05e11d942d77c1b6bff45d12bbb1a2bd6)
-- 🌟 增加 `okButtonDisabled` and `cancelButtonDisabled` 属性用于禁用确定和取消按钮。[#10955](https://github.com/ant-design/ant-design/pull/10955)
 - 🌟 Cascader 新增 fieldNames 并废弃拼写错误的 filedNames。[#10896](https://github.com/ant-design/ant-design/issues/10896)
 - 🐞 修复时间轴不能与`Tooltip`一起使用的问题。[0e3b67e](https://github.com/ant-design/ant-design/commit/0e3b67e9999d867cc304f3be61a8a042a2ab92ee)
 - 🐞 修复当 Avatar 自定义大小时，圆角不改变的问题。[e1e6523](https://github.com/ant-design/ant-design/commit/e1e6523452286ba56f20b73abad762a58ea7d7bc)

components/modal/Modal.tsx

@@ -140,8 +140,6 @@ export default class Modal extends React.Component<ModalProps, {}> {
     confirmLoading: false,
     visible: false,
     okType: 'primary' as ButtonType,
-    okButtonDisabled: false,
-    cancelButtonDisabled: false,
   };
 
   static propTypes = {