Type error: wp_cache_delete can return null

Due to this method returning bool|null:
https://github.com/litespeedtech/lscache_wp/blob/ae7624ebd11fd4b832987a7c1a0779e5488f078c/src/object-cache.cls.php#L740-L749

wp_cache_delete returns bool|null even though it's documented as returning bool:
https://github.com/litespeedtech/lscache_wp/blob/ae7624ebd11fd4b832987a7c1a0779e5488f078c/src/object.lib.php#L202-L212

Read src/object-cache.cls.php lines 740-749 and src/object.lib.php lines 202-212, then trace how wp_cache_delete produces its result. Confirm the documented boolean contract against the current return paths and verify that the related cache method no longer exposes an unexpected null result.

Written by the indexing model from the issue text.