Configure branches for unrolled perf builds for bors

[Kobzol]

Adds new branches that will be used by bors to unroll branches for perf. builds (this functionality will be ported over from rustc-perf).

Historically we had some issues with bors creating these branches, so it would be good if they could be pre-created manually first.

After the functionality is ported and we test that it works fine, I will remove the push access of rust-timer and the old try-perf and try-tmp branches.

[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
[INFO  rust_team::sync] 💻 Repo Diffs:
    📝 Editing repo 'rust-lang/rust':
      Rulesets:
          Creating 'automation/bors/try-perf'
            Include Branches: ["refs/heads/automation/bors/try-perf"]
            Bypass Actors: [RulesetBypassActor { actor_id: 278306, actor_type: Integration, bypass_mode: Always }]
            Required approvals: 1
            Restrict updates: true
          Creating 'automation/bors/try-perf-merge'
            Include Branches: ["refs/heads/automation/bors/try-perf-merge"]
            Bypass Actors: [RulesetBypassActor { actor_id: 278306, actor_type: Integration, bypass_mode: Always }]
            Required approvals: 1
            Restrict updates: true
      Environments:
        🔄 Update: bors
            Adding branches: automation/bors/try-perf

[Kobzol]

Could you also create the branches on https://github.com/rust-lang/rust/branches/active? Thanks! Pushing latest main to them should be enough.

[ubiratansoares]

Hopefully everything is set now :)