breaking: Remove Spotlight Django integration

[BYK]

We are moving away from Spotlight's overlay mode with its new versions so removing this integration from the SDK too.

Ref getsentry/spotlight#891

[codecov]

Codecov Report

✅ All modified and coverable lines are covered by tests.
✅ Project coverage is 84.78%. Comparing base (ebd77f2) to head (e610536).
⚠️ Report is 1 commits behind head on potel-base.
✅ All tests successful. No failed tests found.

Additional details and impacted files

@@              Coverage Diff               @@
##           potel-base    #4747      +/-   ##
==============================================
+ Coverage       84.56%   84.78%   +0.22%     
==============================================
  Files             158      158              
  Lines           16162    16093      -69     
  Branches         2575     2564      -11     
==============================================
- Hits            13667    13645      -22     
+ Misses           1700     1655      -45     
+ Partials          795      793       -2     

Files with missing lines	Coverage Δ
sentry_sdk/spotlight.py	81.39% <ø> (+23.35%)	⬆️

... and 3 files with indirect coverage changes