gh-127712: Fix `secure` argument of `logging.handlers.SMTPHandler` (GH-127726)

GH-127712: Fix `secure` argument of `logging.handlers.SMTPHandler`

Python 3.12 removed support for the `keyfile` and `certfile` parameters
in `smtplib.SMTP.starttls()`, requiring a `ssl.SSLContext` instead.
`SMTPHandler` now creates a context from the `secure` tuple and passes
that to `starttls`.