Merge pull request #2098 from nellshamrell/update-twir-default-branch

updates default this-week-in-rust branch name to main

Author: marcoieni

repos/rust-lang/this-week-in-rust.toml

@@ -9,5 +9,5 @@ twir-reviewers = "write"
 twir = "write"
 
 [[branch-protections]]
-pattern = "master"
+pattern = "main"
 required-approvals = 0