Incorrect `@since` annotation for `wp_get_user_request()`

[swissspidy]

wp_get_user_request_data() was renamed to wp_get_user_request() in [47245] in WP 5.4.0, and the former deprecated. However, the docblock for wp_get_user_request() wasn't updated and wrongly indicates it was introduced in 4.9.6, when it was actually 5.4.0

Trac ticket: https://core.trac.wordpress.org/ticket/65132

This PR corrects the @since annotation for wp_get_user_request() in src/wp-includes/user.php, updating it from 4.9.6 to 5.4.0.

The function wp_get_user_request_data() was renamed to wp_get_user_request() in WordPress 5.4.0 (changeset 47245), and the original function was deprecated. However, the docblock for wp_get_user_request() was not updated at the time and incorrectly stated that it was introduced in version 4.9.6.

### Use of AI Tools

AI assistance: Yes
Model(s): Gemini 3.1 Pro
Used for: Drafting this PR description.

[gaurangsondagar]

Patch Report Testing

Patch Tested: ​https://github.com/WordPress/wordpress-develop/pull/11653/commits/23f367fb7cac4861204b7eaf57190e12250e25d7

Environment:

• PHP: 8.2.29
• WordPress: 7.0-RC2-62242
• Web server: Apache
• Database: MySQL
• Browser: Chrome
• OS: Ubuntu 22.04.5 LTS

Result:
This Patch corrects the @since annotation for wp_get_user_request() in src/wp-includes/user.php, updating it from 4.9.6 to 5.4.0.

Screenshot for reference:
​https://snipboard.io/dR1uBN.jpg

[nikunj8866]

I've reviewed the PR and left some feedback. Please take a look.

Adds the missing @since 5.4.0 description to the wp_get_user_request() DocBlock, noting that the function was renamed from wp_get_user_request_data().