fix: Prevent data race in email sending#494

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andrew-pavlov-ua wants to merge 2 commits intosendgrid:mainfrom apvsyp:main-copy

+89-23

Commits on Feb 10, 2025

Added a test to check thread safety, it failed with race 'detected during execution'
andrew-pavlov-ua
committed

Commits on Feb 11, 2025

Fixed data race when sending emails by changing Client struct
andrew-pavlov-ua
committed