Latest version of pyopenssl breaks gsutil signurl

[adamk9k]

Hey there, this https://github.com/pyca/pyopenssl/pull/1223/files change in pyopenssl removed load_pkcs12 from OpenSSL.crypto. signurl used it directly https://github.com/GoogleCloudPlatform/gsutil/blob/master/gslib/commands/signurl.py#L57 and with it now missing it triggers a misleading error message that pyopenssl is not installed.

Also listed in the changelog https://github.com/pyca/pyopenssl/blob/c8b8c1eed352fc48cfe9e7052094857249525176/CHANGELOG.rst#backward-incompatible-changes (although there's a typo and they say they removed OpenSSL.crypto.loads_pkcs12).

Sorry I can't contribute a fix

[h4xnoodle]

To get around this, you can uninstall the latest and pip3 install pyopenssl==23.2.0 to use the version of pyopenssl that will work out here.