feat(loguru): Capture extra

[sentrivana]

Description

Add extra from records to attributes.

Note: This doesn't fix #4475 since we still don't have a good way to get the raw, unformatted message, but it's an improvement.

Issues

Related to #4475

Reminders

• Please add tests to validate your changes, and lint your code using tox -e linters.
• Add GH Issue ID & Linear ID (if applicable)
• PR title should use conventional commit style (feat:, fix:, ref:, meta:)
• For external contributors: CONTRIBUTING.md, Sentry SDK development docs, Discord community

[codecov]

Codecov Report

❌ Patch coverage is 71.42857% with 2 lines in your changes missing coverage. Please review.
✅ Project coverage is 83.95%. Comparing base (b8a0db2) to head (5d7e6fa).
⚠️ Report is 3 commits behind head on master.
✅ All tests successful. No failed tests found.

Files with missing lines	Patch %	Lines
sentry_sdk/integrations/loguru.py	71.42%	1 Missing and 1 partial ⚠️

Additional details and impacted files

@@            Coverage Diff             @@
##           master    #5096      +/-   ##
==========================================
- Coverage   84.01%   83.95%   -0.06%     
==========================================
  Files         180      180              
  Lines       18004    18010       +6     
  Branches     3200     3203       +3     
==========================================
- Hits        15126    15121       -5     
- Misses       1906     1915       +9     
- Partials      972      974       +2     

Files with missing lines	Coverage Δ
sentry_sdk/integrations/loguru.py	84.21% <71.42%> (-1.19%)	⬇️

... and 4 files with indirect coverage changes