Setup opentelemetry patch only once

[sl0thentr0py]

All our integrations follow the setup_once logic while the otel patching was being done for each Client again leading to recursive patching.
This was revealed by removing the transport test forks.

[codecov]

Codecov Report

All modified and coverable lines are covered by tests ✅

Project coverage is 84.90%. Comparing base (dbb8ead) to head (cab4fcc).
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    #4595      +/-   ##
==============================================
- Coverage       84.94%   84.90%   -0.05%     
==============================================
  Files             158      158              
  Lines           15369    15372       +3     
  Branches         2430     2431       +1     
==============================================
- Hits            13055    13051       -4     
- Misses           1560     1567       +7     
  Partials          754      754              

Files with missing lines	Coverage Δ
sentry_sdk/opentelemetry/tracing.py	91.89% <100.00%> (+0.71%)	⬆️

... and 2 files with indirect coverage changes

[szokeasaurusrex]

lgtm, but looks like it still could be possible for the opentelemetry readable span to be patched mutiple times in a multithreaded context if there is a race condition.

If it is possible that multiple threads would attempt the patch concurrently, we should make the code thread safe