Rollup merge of #34664 - alexcrichton:bump, r=brson
Rollup merge of #34664 - alexcrichton:bump, r=brson

Bump version to 1.12.0

Beta's now in the forge, let's start working on 1.12.0!

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