Use RH_PERF_BOT_TOKEN for backporting

[lampajr]

Changes proposed

Use machine account @rh-appservices-perf token for backporting purposes.

Check List (Check all the applicable boxes)

• [x] My code follows the code style of this project.
• [ ] My change requires changes to the documentation.
• [ ] I have updated the documentation accordingly.
• [ ] All new and existing tests passed.

[lampajr]

Unfortunately I think the only way to check this is actually working is to see it in action the first time we need it.