minor #45234 Remove 5.3 from PR template (ogizanagi)
minor #45234 Remove 5.3 from PR template (ogizanagi)

This PR was merged into the 4.4 branch.

Discussion
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Remove 5.3 from PR template

| Q             | A
| ------------- | ---
| Branch?       | 4.4 <!-- see below -->
| Bug fix?      | no
| New feature?  | no <!-- please update src/**/CHANGELOG.md files -->
| Deprecations? | no <!-- please update UPGRADE-*.md and src/**/CHANGELOG.md files -->
| Tickets       | N/A <!-- prefix each issue number with "Fix #", no need to create an issue if none exist, explain below instead -->
| License       | MIT
| Doc PR        | N/A

Commits
-------

afada38d42 Remove 5.3 from PR template

nicolas-grekas/symfony,mpdude/symfony,mpdude/symfony,paradajozsef/symfony,symfony/symfony,tucksaun/symfony,d-ph/symfony,damienalexandre/symfony,xabbuh/symfony,damienalexandre/symfony,d-ph/symfony,HeahDude/symfony,zerkms/symfony,zerkms/symfony,stof/symfony,damienalexandre/symfony,HeahDude/symfony,mpdude/symfony,damienalexandre/symfony,tucksaun/symfony,symfony/symfony,derrabus/symfony,zerkms/symfony,nicolas-grekas/symfony,sgehrig/symfony,stof/symfony,curry684/symfony,phramz/symfony,curry684/symfony,nicolas-grekas/symfony,sgehrig/symfony,HeahDude/symfony,paradajozsef/symfony,HeahDude/symfony,d-ph/symfony,stof/symfony,nicolas-grekas/symfony,xabbuh/symfony,xabbuh/symfony,phramz/symfony,d-ph/symfony,sgehrig/symfony,zerkms/symfony,phramz/symfony,derrabus/symfony,stof/symfony,derrabus/symfony,curry684/symfony,tucksaun/symfony,derrabus/symfony,symfony/symfony,tucksaun/symfony,xabbuh/symfony,sgehrig/symfony,curry684/symfony,symfony/symfony,mpdude/symfony,paradajozsef/symfony,paradajozsef/symfony,phramz/symfony