save certificate for use in tests

[dholth]

Description

An attempt to speed up the tests by not creating a new certificate all the time.

To address codspeed regressions in #13735

Checklist - did you ...

• Add a file to the news directory (using the template) for the next release's release notes?
• Add / update necessary tests?
• Add / update outdated documentation?

[kenodegard]

you can also update the test to isolate the code to benchmark versus the setup/teardown:

@pytest.mark.benchmark
def test(benchmark):
    # setup

    @benchmark
    def _():
        # code to benchmark

    # teardown

[codspeed-hq]

CodSpeed Performance Report

Merging #13750 will degrade performances by 66.66%

_{Comparing httpserver-certificate (9578137) with main (11c21d5)}

Summary

❌ 2 regressions
✅ 19 untouched benchmarks

⚠️ Please fix the performance issues or acknowledge them on CodSpeed.

Benchmarks breakdown

	Benchmark	main	httpserver-certificate	Change
❌	test_jlap_fetch_ssl[False]	359.9 ms	936.8 ms	-61.58%
❌	test_jlap_fetch_ssl[True]	619.1 ms	1,856.9 ms	-66.66%

[dholth]

Sounds good, looking at those functions that happened to be tagged as benchmark, a lot of what it's doing is test setup.
It would make more sense to benchmark single functions like fetch.download_and_hash or repo.repodata(). Will also have to consider whether those would mess with the "count function calls with a mocker" part of the test.

[jezdez]

Couldn't we just depend on Werkzeug in the tests? Aren't we already using flask in the tests?

[jezdez]

Suggested change

	* Use static ssl certificate in test suite to save time (#13750)
	* Use static ssl certificate in test suite to save time. (#13750)

[dholth]

It looks like this doesn't speed up the tests as hoped.