[php-src] PR #23440: ext/standard: Adds and modifies XFAIL tests for filter bucket leaks

Pull Request: https://github.com/php/php-src/pull/23440 Author: NickSdot I wanted to [fix](https://github.com/php/php-src/compare/master...NickSdot:php__php-src:tests/sfr-xfail-warn-fix) two warn: XFAIL section but test passes but found https://github.com/php/php-src/pull/20058 which already attempts fixing the leaks; don't want to open an overlapping one. However, the PR is already a bit older -- currently builds without leak detection warn because XFAIL is too broad. So here we change to use SKIPIF to "xfail", "xleak", or skip only where relevant so that we for the time being have no warnings where no leaks can be detected and tests pass. Additionally, two tests for related issues that surfaced were added (also mentioned in https://github.com/php/php-src/pull/20058#issuecomment-5035247768) . Should this target 8.4 (20058 still targets 8.3)? cc @Girgias the two modified tests were added by you, are you okay with this change? cc @iliaal would you want to look at the two added tests?