doc: `http.setMaxIdleHTTPParsers` is missing a traditional function signature

### Version

main

### Platform

n/a

### Subsystem

doc

### What steps will reproduce the bug?

_No response_

### How often does it reproduce? Is there a required condition?

_No response_

### What is the expected behavior?

_No response_

### What do you see instead?

It seems to be using a setter/property-style API documentation format.

### Additional information

_No response_