Fix race condition in consultation creation

[sainak]

This pull request fixes a race condition that allowed duplicate consultations to be created. The issue was caused by concurrent requests creating consultations for the same patient. The fix ensures that only one consultation is created for each patient, preventing duplicates.

[codecov]

Codecov Report

Attention: Patch coverage is 72.97297% with 20 lines in your changes missing coverage. Please review.

Project coverage is 63.77%. Comparing base (e95d98d) to head (af9da5b).
Report is 6 commits behind head on develop.

Files	Patch %	Lines
...e/facility/api/serializers/patient_consultation.py	62.50%	11 Missing and 7 partials ⚠️
care/utils/lock.py	90.90%	1 Missing and 1 partial ⚠️

Additional details and impacted files

@@             Coverage Diff             @@
##           develop    #2299      +/-   ##
===========================================
+ Coverage    63.69%   63.77%   +0.07%     
===========================================
  Files          238      239       +1     
  Lines        13384    13407      +23     
  Branches      1908     1908              
===========================================
+ Hits          8525     8550      +25     
+ Misses        4509     4508       -1     
+ Partials       350      349       -1     

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