Fix #294 - Nswag 8618 warning by upgrading Nswag

[johnml1135]

This change is 

[codecov-commenter]

Codecov Report

Attention: Patch coverage is 77.77778% with 26 lines in your changes missing coverage. Please review.

Project coverage is 56.58%. Comparing base (a111c67) to head (bbf5978).

Files with missing lines	Patch %	Lines
src/Serval/src/Serval.Client/Client.g.cs	77.77%	23 Missing and 3 partials ⚠️

Additional details and impacted files

@@            Coverage Diff             @@
##             main     #472      +/-   ##
==========================================
- Coverage   56.63%   56.58%   -0.05%     
==========================================
  Files         275      275              
  Lines       14174    14174              
  Branches     1902     1908       +6     
==========================================
- Hits         8028     8021       -7     
- Misses       5557     5563       +6     
- Partials      589      590       +1     

☔ View full report in Codecov by Sentry.
📢 Have feedback on the report? Share it here.

[ddaspit]

Reviewed 6 of 6 files at r1, all commit messages.
Reviewable status: complete! all files reviewed, all discussions resolved (waiting on @johnml1135)