fix(seer): Report anomaly detection issues by error

[kcons]

There are multiple ways requests to Seer can fail, and we'd like to track them independently.
This embeds the failure text in the logger call to group them separately, and also switches to
logger.warning because logger.error changes block deploy.

[codecov]

Codecov Report

❌ Patch coverage is 0% with 3 lines in your changes missing coverage. Please review.
✅ All tests successful. No failed tests found.

Files with missing lines	Patch %	Lines
.../sentry/seer/anomaly_detection/get_anomaly_data.py	0.00%	3 Missing ⚠️

Additional details and impacted files

@@             Coverage Diff             @@
##           master   #101982      +/-   ##
===========================================
+ Coverage   80.58%    80.97%   +0.39%     
===========================================
  Files        8729      8729              
  Lines      388387    388389       +2     
  Branches    24625     24625              
===========================================
+ Hits       312977    314505    +1528     
+ Misses      75050     73524    -1526     
  Partials      360       360