Fixed deadlock on sync token updating

[alex268]

No description provided.

[codecov-commenter]

Codecov Report

❌ Patch coverage is 60.00000% with 2 lines in your changes missing coverage. Please review.
✅ Project coverage is 63.35%. Comparing base (5a59fc3) to head (cd01dc8).

Files with missing lines	Patch %	Lines
...ain/java/tech/ydb/core/impl/BaseGrpcTransport.java	33.33%	1 Missing and 1 partial ⚠️

Additional details and impacted files

@@                 Coverage Diff                  @@
##             release_v2.4.0     #563      +/-   ##
====================================================
+ Coverage             63.28%   63.35%   +0.06%     
+ Complexity             2478     2476       -2     
====================================================
  Files                   335      334       -1     
  Lines                 13960    13947      -13     
  Branches               1410     1409       -1     
====================================================
+ Hits                   8835     8836       +1     
+ Misses                 4496     4479      -17     
- Partials                629      632       +3     

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