Clean up loggers: remove make_logger, use standard logging

[edgarcosta]

Summary

Resolves #6885. Each LMFDB module had its own logging.Logger instance created via make_logger(), resulting in 55+ redundant loggers with partially broken configuration logic (the logfocus feature in make_logger was noted in the code itself as "NEVER BE TRUE").

This PR removes make_logger() entirely and replaces all usage with standard logging.getLogger("lmfdb").

Changes

• lmfdb/logger/utils.py: Removed the make_logger() function. LmfdbFormatter is retained (still used by start.py).
• lmfdb/logger/__init__.py: Removed make_logger from imports and __all__.
• lmfdb/logger/start.py: Removed dead logfocus code that set levels on per-module named loggers no longer in use.
• 75 files across the codebase: Removed all from lmfdb.logger import make_logger imports and make_logger() calls.
  • 38 files had loggers that were created but never used — these were simply deleted.
  • 20 files that actively use their logger were updated to logging.getLogger("lmfdb").

Net result: 54 insertions, 181 deletions — removing ~130 lines of unnecessary code.

How it works

All logging now goes through a single "lmfdb" logger, which propagates to the root logger already configured in start.py with the appropriate formatter and level. This is equivalent to using app.logger (since Flask names it after app.import_name), but uses standard Python logging to avoid circular import issues.

[roed314]

Oops, see #6889.