Auto merge of #46284 - SimonSapin:deprecate-formatter-flags, r=sfackler
Auto merge of #46284 - SimonSapin:deprecate-formatter-flags, r=sfackler

Deprecate the Formatter::flags method, fix #46237

This fixes #46237.

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