Rollup merge of #33631 - solson:ignore-rustbuild-config, r=alexcrichton
Rollup merge of #33631 - solson:ignore-rustbuild-config, r=alexcrichton

rustbuild: Ignore user config.toml file.

r? @eddyb

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