Merge pull request #2010 from Kobzol/rustup-main

Rename default branch of rustup to `main`

Author: marcoieni

repos/rust-lang/rustup.toml

@@ -8,5 +8,5 @@ bots = ["rustbot", "renovate"]
 rustup = "maintain"
 
 [[branch-protections]]
-pattern = "master"
+pattern = "main"
 ci-checks = ["conclusion"]