doc: update pull request template in the contributing guide

Refs: nodejs#19125

Author: Hackzzila

doc/guides/contributing/pull-requests.md

@@ -334,9 +334,6 @@ Contributors guide: https://github.com/nodejs/node/blob/master/CONTRIBUTING.md
 - [ ] tests and/or benchmarks are included
 - [ ] documentation is changed or added
 - [ ] commit message follows [commit guidelines](https://github.com/nodejs/node/blob/master/doc/guides/contributing/pull-requests.md#commit-message-guidelines)
-
-#### Affected core subsystem(s)
-<!-- Provide affected core subsystem(s) (like doc, cluster, crypto, etc). -->
 ```
 
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