Remove timezonefinder dependency

[Copilot]

This PR removes the timezonefinder dependency that was automatically looking up timezones based on latitude/longitude coordinates in the Location class.

Problem

The timezonefinder dependency alone is 50M+ in size and depends on numpy (another 16M+), resulting in a total bloat of 66M+ for a feature with no known users. This large dependency size also prevents pre-built binaries from being available for ARM platforms.

Solution

• Removed dependency: Removed timezonefinder >= 6.2.0, < 7 from pyproject.toml
• Simplified behavior: Location.timezone now remains None unless explicitly provided during construction
• Removed automatic lookup: Eliminated the __post_init__ method that performed timezone lookup from coordinates
• Updated tests: Removed timezone finder mocking and updated tests to verify the new behavior
• Added documentation: Comprehensive RELEASE_NOTES.md with migration guide

Breaking Change

This is a breaking change shipped in a patch release because this feature has no known users. The timezone lookup is no longer performed automatically.

Migration for Users Who Need Timezone Lookup

If timezone lookup from coordinates is needed, install timezonefinder separately and implement manual lookup:

# Install: pip install timezonefinder
from timezonefinder import TimezoneFinder
from zoneinfo import ZoneInfo
from frequenz.client.microgrid import Location

tf = TimezoneFinder()
tz_name = tf.timezone_at(lat=52.52, lng=13.405)
timezone = ZoneInfo(tz_name) if tz_name else None
location = Location(latitude=52.52, longitude=13.405, timezone=timezone)

Before/After

Before:

# Automatic timezone lookup
location = Location(latitude=52.52, longitude=13.405)
print(location.timezone)  # ZoneInfo('Europe/Berlin') - looked up automatically

After:

# Explicit timezone only
location = Location(latitude=52.52, longitude=13.405)
print(location.timezone)  # None - no automatic lookup

# Or provide explicitly
location = Location(latitude=52.52, longitude=13.405, timezone=ZoneInfo('Europe/Berlin'))
print(location.timezone)  # ZoneInfo('Europe/Berlin')

Fixes #75.

[llucax]

Please also update the RELEASE_NOTES.md file to include the change of behavior and dependencies. Recommend users installing timezonefinder themselves if they need to get a timezone from the coordinates (with a small example). Clarify this change is shipped in a patch release even if there is a breaking change because this feature have no known users.

[Copilot]

Please also update the RELEASE_NOTES.md file to include the change of behavior and dependencies. Recommend users installing timezonefinder themselves if they need to get a timezone from the coordi...

Updated RELEASE_NOTES.md with comprehensive documentation of the breaking change, migration guide with code examples, and clarification that this is shipped in a patch release despite being a breaking change because the feature has no known users. Commit 7958389

[Copilot]

Pull Request Overview

This PR removes the timezonefinder dependency to reduce package size by 66M+ and improve ARM platform compatibility. The automatic timezone lookup functionality in the Location class has been removed as a breaking change due to having no known users.

• Removed timezonefinder and numpy dependencies (66M+ size reduction)
• Eliminated automatic timezone lookup from latitude/longitude coordinates
• Simplified Location class behavior to only use explicitly provided timezone values

Reviewed Changes

Copilot reviewed 4 out of 4 changed files in this pull request and generated 1 comment.

File	Description
pyproject.toml	Removed timezonefinder dependency from project dependencies
src/frequenz/client/microgrid/_metadata.py	Removed timezone lookup logic and simplified Location class
tests/test_metadata.py	Updated tests to verify new behavior without timezone lookup
RELEASE_NOTES.md	Added comprehensive migration guide and breaking change documentation