Remove unused forms and stats views

[mrchrisadams]

This pull request removes a bunch of unused code and features to simplify the codebase.

The most important changes include the removal of the unused UserUpdateView, the deletion of the backfill_stats management command and associated tests, and the cleanup of various files in the apps/greencheck directory, as well as removing the stats views that were built nearly three years ago, but didn't really get launched.

Removal of UserUpdateView:

• apps/accounts/urls.py: Removed the UserUpdateView import and URL path. [1] [2]
• apps/accounts/views.py: Removed the UserUpdateView class and its associated form import. [1] [2] [3]

Deletion of backfill_stats management command:

• apps/greencheck/management/commands/backfill_stats.py: Removed the entire backfill_stats management command file.
• apps/greencheck/tests/management/test_backfill_stats.py: Removed the associated tests for the backfill_stats command.

Cleanup in apps/greencheck:

• apps/greencheck/models/__init__.py: Removed the import for stats.
• apps/greencheck/tests/dummy_greencheck_stat_data.py: Removed commented-out SQL queries.
• apps/greencheck/tests/views/test_stats_view.py: Removed the TestDailyStatsView class and related imports.
• apps/greencheck/url2green.py: Removed the entire url2green utility module.
• apps/greencheck/urls.py: Removed the URL patterns and related imports.
• apps/greencheck/views.py: Removed unused imports and cleaned up the file.

Other changes:

• .tool-versions: Removed the Python version specification.

[github-actions]

Old Energy Estimation

Eco-CI Output:

Label	🖥 avg. CPU utilization [%]	🔋 Total Energy [Joules]	🔌 avg. Power [Watts]	Duration [Seconds]
Total Run (incl. overhead)	18.459	556.698	3.35	166
checkout	8.54	3.58249	3.58	1
pip install uv wheel	8.64	3.5807	1.79	2
pip install requirements	63.832	31.1823	5.20	6
pytest	16.9709	518.352	3.34	155

🌳 CO2 Data:
City: Chicago, Lat: 41.8874, Lon: -87.6318
IP: 172.183.107.22
CO₂ from energy is: 0.221009106 g
CO₂ from manufacturing (embodied carbon) is: 0.047362092 g
Carbon Intensity for this location: 397 gCO₂eq/kWh
SCI: 0.268371 gCO₂eq / pipeline run emitted

[github-actions]

Eco-CI Output:

Label	🖥 avg. CPU utilization [%]	🔋 Total Energy [Joules]	🔌 avg. Power [Watts]	Duration [Seconds]
Total Run (incl. overhead)	14.837	740.412	3.10	239
checkout	13.04	3.73622	1.87	2
pip install uv wheel	22.355	8.04218	2.68	3
pip install requirements	61.27	42.1893	6.03	7
pytest	13.1949	686.444	3.06	224

🌳 CO2 Data:
City: Boydton, Lat: 36.6676, Lon: -78.3875
IP: 20.55.223.80
CO₂ from energy is: 0.293943564 g
CO₂ from manufacturing (embodied carbon) is: 0.068190000 g
Carbon Intensity for this location: 397 gCO₂eq/kWh
SCI: 0.362134 gCO₂eq / pipeline run emitted