Add option to pass a timezone into richhandler for log timestamps

[PokkaKiyo]

Type of changes

• Bug fix
• New feature
• Documentation / docstrings
• Tests
• Other

Checklist

• I've run the latest black with default args on new code.
• I've updated CHANGELOG.md and CONTRIBUTORS.md where appropriate.
• I've added tests for new code.
• I accept that @willmcgugan may be pedantic in the code review.

Description

Add option to pass a timezone into RichHandler for log timestamps.

Currently, the timestamp produced by RichHandler ignores the "%z" field if it is passed into the dateformat, likely because the datetime object created in RichHandler.render is timezone-naive. We can make it timezone-aware by passing in the expected timezone when calling datetime.fromtimestamp on the log message's timestamp.

The current alternative to doing this would be something like

import logging
from datetime import UTC, datetime

from rich.logging import RichHandler
from rich.text import Text

logging.basicConfig(
    level="NOTSET",
    format="%(message)s",
    handlers=[
        RichHandler(
            rich_tracebacks=True,
            tracebacks_show_locals=True,
            log_time_format=lambda dt: Text(
                datetime.fromtimestamp(dt.timestamp(), tz=UTC).strftime("%Y-%m-%dT%H:%M:%S%z")
            ),
        )
    ],
)
logging.debug("hello")  # 2024-11-24T08:53:00+0000 DEBUG    hello