make_ssl_certs: run at build time, update reference test data automatically

Bug report

Bug description:

As discussed here:
https://github.com/python/cpython/pull/107594

make_ssl_certs.py has a few shortcomings. In particular:

• it generates certificates, but does not update reference data in tests that use them, instead asking the user to copy paste the data by hand (expiration dates and serial numbers in particular)
• it is supposed to be run by hand and isn't executed in builds, which means its output has to be checked into git, cluttering the source tree, and complicating reviews of pull requests that change that output.
• expiration dates are hardcoded into the tool and can't be passed in as parameters

CPython versions tested on:

CPython main branch

Operating systems tested on:

Linux

Linked PRs

• gh-119401

先閱讀 make_ssl_certs.py 和連結的 PR gh-119401，接著檢查使用其憑證的參考測試資料。當憑證產生會在建置期間執行、自動更新參考資料，並且接受將到期日期作為參數而不需要簽入產生的輸出時，工作就完成了。