gh-108303: Move all certificates to Lib/test/certdata/

[sobolevn]

This is a big one: I moved all .pem and ssl related files to a single test helper diractory:

» tree Lib/test/certdata Lib/test/certdata ├── allsans.pem ├── badcert.pem ├── badkey.pem ├── capath │ ├── 4e1295a3.0 │ ├── 5ed36f99.0 │ ├── 6e88d7b8.0 │ ├── 99d0fa06.0 │ ├── b1930218.0 │ └── ceff1710.0 ├── ffdh3072.pem ├── idnsans.pem ├── keycert.passwd.pem ├── keycert.pem ├── keycert2.pem ├── keycert3.pem ├── keycert4.pem ├── keycertecc.pem ├── make_ssl_certs.py ├── nokia.pem ├── nosan.pem ├── nullbytecert.pem ├── nullcert.pem ├── pycacert.pem ├── pycakey.pem ├── revocation.crl ├── secp384r1.pem ├── selfsigned_pythontestdotnet.pem ├── ssl_cert.pem ├── ssl_key.passwd.pem ├── ssl_key.pem └── talos-2019-0758.pem 

I haven't touched their contents or permissions (at least I hope so), so let's what the CI will say :)

I've also checked that Lib/test/certdata/make_ssl_certs.py script still works. It produces new certificates as it should.

• Issue: Move test files into test subdirectories #108303

[sobolevn]

Aaaand it broke :(

[vstinner]

LGTM, merged, thanks @sobolevn :-)

[miss-islington]

Thanks @sobolevn for the PR, and @vstinner for merging it 🌮🎉.. I'm working now to backport this PR to: 3.12.
🐍🍒⛏🤖

[bedevere-app]

GH-109682 is a backport of this pull request to the 3.12 branch.

[miss-islington]

Thanks @sobolevn for the PR, and @vstinner for merging it 🌮🎉.. I'm working now to backport this PR to: 3.11.
🐍🍒⛏🤖

[bedevere-app]

GH-109683 is a backport of this pull request to the 3.11 branch.