fix(langchain): Ensure no duplicate SentryLangchainCallback

[szokeasaurusrex]

Ensure that SentryLangchainCallback does not get added twice by also checking the inheritable_callbacks

Fixes #4443

[codecov]

Codecov Report

All modified and coverable lines are covered by tests ✅

Project coverage is 80.68%. Comparing base (901b579) to head (ccdd82f).

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    RuntimeError: Error parsing XML
    
    Caused by:
        0: ill-formed document: close tag `</testsuite>` does not match any open tag
        1: close tag `</testsuite>` does not match any open tag

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Additional details and impacted files

@@                             Coverage Diff                             @@
##           szokeasaurusrex/refactor-langchain-args    #4485      +/-   ##
===========================================================================
+ Coverage                                    80.63%   80.68%   +0.04%     
===========================================================================
  Files                                          142      142              
  Lines                                        16037    16021      -16     
  Branches                                      2741     2741              
===========================================================================
- Hits                                         12932    12926       -6     
+ Misses                                        2239     2230       -9     
+ Partials                                       866      865       -1     

Files with missing lines	Coverage Δ
sentry_sdk/integrations/langchain.py	71.55% <100.00%> (+1.11%)	⬆️

... and 6 files with indirect coverage changes