Deprecate Span.set_data

[antonpirker]

This is the first part of #4102

[codecov]

Codecov Report

All modified and coverable lines are covered by tests ✅

Project coverage is 79.53%. Comparing base (d0d70a5) to head (ca70d2b).
Report is 8 commits behind head on master.

✅ All tests successful. No failed tests found.

Additional details and impacted files

@@            Coverage Diff             @@
##           master    #4222      +/-   ##
==========================================
+ Coverage   79.48%   79.53%   +0.05%     
==========================================
  Files         141      141              
  Lines       15809    15810       +1     
  Branches     2703     2703              
==========================================
+ Hits        12565    12574       +9     
+ Misses       2382     2375       -7     
+ Partials      862      861       -1     

Files with missing lines	Coverage Δ
sentry_sdk/tracing.py	77.77% <100.00%> (+0.04%)	⬆️

... and 4 files with indirect coverage changes

[szokeasaurusrex]

Same comment as #4221; it looks like we use Span.set_data in many places – I think we should remove those usages first to avoid potentially causing users to encounter this deprecation warning

[antonpirker]

Then the deprecation message will only happen in 3.0. So I am closing this.