test: Add asv benchmark jobs to CI

[Illviljan]

Add a benchmarking ci, it will run if run-benchmark label is set.

• [x] Closes #231

Inspired by:

• https://labs.quansight.org/blog/2021/08/github-actions-benchmarks/
• https://github.com/pydata/xarray/pull/5796
• https://github.com/scikit-image/scikit-image/pull/5424

[codecov[bot]]

Codecov Report

Merging #234 (324c802) into master (42b1bc3) will not change coverage. The diff coverage is n/a.

:exclamation: Current head 324c802 differs from pull request most recent head dcdd3a3. Consider uploading reports for the commit dcdd3a3 to get more accurate results

@@           Coverage Diff           @@
##           master     #234   +/-   ##
=======================================
  Coverage   98.77%   98.77%           
=======================================
  Files          40       40           
  Lines         978      978           
=======================================
  Hits          966      966           
  Misses         12       12           

Flag	Coverage Δ
unittests	98.77% <ø> (ø)

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[Illviljan]

Ok this is ready for review now, it passes on my local fork at least https://github.com/Illviljan/ruptures/pull/1. If you add the label run-benchmark the benchmark will run.

The benchmarks probably needs a bit more thought by someone more experienced. But that's for another PR I think.