Workaround: Suppress `curl_close()` deprecation warning from Guzzle

[ruflin]

A workaround was added to tests/bootstrap.php to suppress a deprecation warning for curl_close() originating from the guzzlehttp/guzzle dependency.

Problem

Running the test suite triggers a deprecation warning because guzzlehttp/guzzle (version ^7.2) uses the curl_close() function, which is deprecated as of PHP 8.5. An attempt to update Guzzle via composer update did not resolve the issue, as the latest version compatible with the project's constraints still includes the deprecated function call.

Workaround Implemented

To maintain clean test output and avoid test failures due to the failOnDeprecation="true" setting, a custom error handler was added to tests/bootstrap.php. This handler specifically intercepts and suppresses the E_USER_DEPRECATED warning related to curl_close().

Next Steps

This workaround is a temporary solution. The ideal fix is to update guzzlehttp/guzzle to a version that no longer uses the deprecated function. This issue serves as a reminder to periodically check for a new Guzzle release that addresses this and, once available, to remove the custom error handler from the bootstrap file.