Validate callback signatures for curl_setopt callback options like CURLOPT_PREREQFUNCTION

[phpstan-bot]

Summary

curl_setopt($ch, CURLOPT_PREREQFUNCTION, $cb) (and the other curl callback
options) accepted any value: passing a callback with the wrong return type was
not reported. PHPStan now knows the exact signature each curl callback option
expects and reports a mismatch such as a bool-returning callback where int
is required.

Changes

• src/Reflection/ParametersAcceptorSelector.php: getCurlOptValueType() now
  maps the curl callback options to a (callable(...): ...)|null value type:
  • CURLOPT_WRITEFUNCTION — callable(CurlHandle, string): int
  • CURLOPT_HEADERFUNCTION — callable(CurlHandle, string): int
  • CURLOPT_READFUNCTION — callable(CurlHandle, resource, int): string
  • CURLOPT_PROGRESSFUNCTION — callable(CurlHandle, int, int, int, int): int
  • CURLOPT_XFERINFOFUNCTION — callable(CurlHandle, int, int, int, int): int
  • CURLOPT_PREREQFUNCTION — callable(CurlHandle, string, string, int, int): int
    The handle parameter is typed CurlHandle on PHP 8+ and resource otherwise,
    reusing the existing PhpVersion::supportsCurlShareHandle() gate. null is
    part of the union so resetting a callback is still allowed.
• Tests: new curl_setopt_callback.php data file plus testCurlSetOptCallback
  in CallToFunctionParametersRuleTest, a PHP 8.4-gated curl_setopt_prereq.php
  / testCurlSetOptPrereqCallback for CURLOPT_PREREQFUNCTION, and a callback
  case added to the curl-setopt-array.php data / testCurlSetOptArray to cover
  the array form.

Root cause

getCurlOptValueType() had entries for bool/int/string/array/resource options
but none for the callback options, so it returned null and no override was
applied — the third curl_setopt argument (and the option array values) stayed
mixed and were never checked. Adding callable value types for the whole family
of curl callback options lets the existing argument-type check verify both the
parameters and the return type of the passed callback.

Test

• testCurlSetOptCallback asserts errors for write/header/read/progress/xferinfo
  callbacks with the wrong return type, and no error for correctly-typed
  callbacks or null.
• testCurlSetOptPrereqCallback (PHP 8.4+) covers the reported
  CURLOPT_PREREQFUNCTION case.
• testCurlSetOptArray now also covers a callback option passed through the
  curl_setopt_array options array.

Fixes phpstan/phpstan#14956