chore: remove "no breaking changes" warning in PR template (#25285)

.github/PULL_REQUEST_TEMPLATE.md

@@ -15,7 +15,6 @@ Contributors guide: https://github.com/electron/electron/blob/master/CONTRIBUTIN
 - [ ] relevant documentation is changed or added
 - [ ] PR title follows semantic [commit guidelines](https://github.com/electron/electron/blob/master/docs/development/pull-requests.md#commit-message-guidelines)
 - [ ] [PR release notes](https://github.com/electron/clerk/blob/master/README.md) describe the change in a way relevant to app developers, and are [capitalized, punctuated, and past tense](https://github.com/electron/clerk/blob/master/README.md#examples).
-- [ ] This is **NOT A BREAKING CHANGE**. Breaking changes may not be merged to master until 11-x-y is branched.
 
 #### Release Notes