Stabilize `Option::filter`.
Stabilize `Option::filter`.

Fixes #45860

GBGamer/rust,GBGamer/rust,GBGamer/rust,graydon/rust,aidancully/rust,GBGamer/rust,graydon/rust,aidancully/rust,aidancully/rust,GBGamer/rust,graydon/rust,aidancully/rust,GBGamer/rust,aidancully/rust,GBGamer/rust,aidancully/rust,GBGamer/rust,graydon/rust,graydon/rust,graydon/rust