Remove renamed allowed_merge_apps

[cuba0001]

Closes #2394

Since allowed_merge_apps was renamed in #2586 and triagebot was updated in rust-lang/triagebot#2464 it can be removed.

[rustbot]

rust_team_data/src/v1.rs has been modified, it is used (as a git dependency) by multiple sub-projects like triagebot, the www.rust-lang.org website and others.

If you are changing the data structures, please make sure that the changes are not going to break serde deserialization (adding a field is fine; removing or renaming a field isn't).

If you must do a breaking change to the format, make sure to coordinate it with all the users of the rust_team_data crate.

[cuba0001]

[ERROR rust_team::validate] validation error: GitHub user Shourya742 changed username to bit-aloo

Looks like need to reload CI when configs are updated.

[jieyouxu]

[ERROR rust_team::validate] validation error: GitHub user Shourya742 changed username to bit-aloo

Looks like need to reload CI when configs are updated.

#2640

[rustbot]

This PR was rebased onto a different main commit. Here's a range-diff highlighting what actually changed.

Rebasing is a normal part of keeping PRs up to date, so no action is needed—this note is just to help reviewers.

[github-actions]

Dry-run check results

[WARN  rust_team::sync] sync-team is running in dry mode, no changes will be applied.
[INFO  rust_team::sync] synchronizing crates-io
[INFO  rust_team::sync] synchronizing github