Rename Browser Performance template jobs

What does this MR do?

This merge request changes the name of the browser performance jobs created by our own CI templates. Due to load_performance also being a testing category, performance is ambiguous now and we'd like to move away from that term. We realized this some time ago in #225914 (closed) but have been waiting for %14.0 since it's technically breaking.

The .latest templates were already updated in %13.12 to allow for a smooth transition: !61522 (merged) / !61523 (merged)

Does this MR meet the acceptance criteria?

Conformity

• I have included a changelog entry, or it's not needed. (Does this MR need a changelog?)
• I have added/updated documentation, or it's not needed. (Is documentation required?)
• I have properly separated EE content from FOSS, or this MR is FOSS only. (Where should EE code go?)
• I have added information for database reviewers in the MR description, or it's not needed. (Does this MR have database related changes?)
• I have self-reviewed this MR per code review guidelines.
• This MR does not harm performance, or I have asked a reviewer to help assess the performance impact. (Merge request performance guidelines)
• I have followed the style guides.

Availability and Testing

• I have added/updated tests following the Testing Guide, or it's not needed. (Consider all test levels. See the Test Planning Process.)
• I have tested this MR in all supported browsers, or it's not needed.
• I have informed the Infrastructure department of a default or new setting change per definition of done, or it's not needed.