mongodb: 1.21.5

2026-02-04T00:00:00+00:00

## What's Changed
* Fix artifact signing by @alcaeus in https://github.com/mongodb/mongo-php-driver/pull/1923
* PHPC-2670: Upgrade libmongoc to 1.30.7 by @alcaeus in https://github.com/mongodb/mongo-php-driver/pull/1930
* PHPC-2636: Respect libbson nesting limit when parsing PHP objects by @alcaeus in https://github.com/mongodb/mongo-php-driver/pull/1934

**Full Changelog**: https://github.com/mongodb/mongo-php-driver/compare/1.21.4...1.21.5