Update to eslint 10 (#36925)

- Enable a few more rules, fix issues. The 2 `value` issues are
false-positives.
- Add exact types for `window.pageData` and
`window.notificationSettings`.
- peerDependencyRules for eslint-plugin-github unrestricted, the plugin
works in v10, but does not declare compatibility, pending
https://github.com/github/eslint-plugin-github/issues/680.
- Added
[eslint-plugin-de-morgan](https://github.com/azat-io/eslint-plugin-de-morgan),
no violations.

---------

Signed-off-by: silverwind <me@silverwind.io>
Signed-off-by: wxiaoguang <wxiaoguang@gmail.com>
Co-authored-by: Claude (Opus 4.6) <noreply@anthropic.com>
Co-authored-by: wxiaoguang <wxiaoguang@gmail.com>
Co-authored-by: Lunny Xiao <xiaolunwen@gmail.com>

web_src/js/components/PullRequestMergeForm.vue

@@ -5,7 +5,7 @@ import {toggleElem} from '../utils/dom.ts';
 
 const {pageData} = window.config;
 
-const mergeForm = pageData.pullRequestMergeForm;
+const mergeForm = pageData.pullRequestMergeForm!;
 
 const mergeTitleFieldValue = shallowRef('');
 const mergeMessageFieldValue = shallowRef('');