Update pyperf to 2.8.1

[pyup-bot]

This PR updates pyperf from 2.6.2 to 2.8.1.

Changelog

2.7.0

---------------------------

* Fix logic in MSR availability test.
Patch by Mike Droettboom.
* Disable tuning TurboBoost setting on non-Intel device.
Patch by Mike Droettboom.
* Include CONFIG_ARGS in Metadata.
Patch by Jeff Glass.
* Support environment variables PYTHON_GIL / PYTHON_CPU_COUNT.
Patch by Donghee Na.

2.6.3

---------------------------

* Support Free-threading CPython (PEP-703) by disabling psutil related features.
Relevant issue: https://github.com/python/cpython/issues/116024.
Patch by Donghee Na.
* Fix mem_max_rss measurement on macOS.
Patch by Mike Droettboom.

Links

• PyPI: https://pypi.org/project/pyperf
• Changelog: https://data.safetycli.com/changelogs/pyperf/