Bug: content-type application/json returns no attributes on /attributes/restSearch

[hazcod]

Expected behavior

When sending a POST request to /attributes/restSearch, no attributes are ever returned if I specify a HTTP request Content-Type: application/json header.
Things do work if I ommit it or use text/javascript.

The result will be along the lines of this, regardless of the request:

{
"Response": { "Attributes": [] }
}

Actual behavior

Get attributes as normal.

Steps to reproduce

Send any POST request to /attributes/restSearch with content-type: application/json.

Version

2.4.166

Operating System

Unsure

Operating System version

Unsure

PHP version

Unsure

Browser

HTTP

Browser version

No response

Relevant log output

No response

Extra attachments

No response

Code of Conduct

• I agree to follow this project's Code of Conduct

[hazcod]

Duped with #8806