release 4.2.0

* Fixed PHP-8.1 compatibility (see gh issues #114, #115 and #118)
* Fixed cookies failing with libcurl >= 7.77 (see gh issue #116)
* Fixed tests using $_ENV instead of getenv() to find executables in PATH (see gh issue #113)
* Added http\Env::reset(): resets internal HTTP request cache (see gh issue #90)