adding current kg deployment date as api endpoint

[iQuxLE]

Related issues

• Closes #Make an API endpoint with release date so we can add it to the UI #1119

Summary

• adds KG_DEPLOYMENT_DATE as env var to docker container via monarch stack v3

• All tests have passed (or issues created for failing tests)

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[codecov]

Codecov Report

Attention: Patch coverage is 90.66667% with 7 lines in your changes missing coverage. Please review.

Project coverage is 72.17%. Comparing base (39ed630) to head (e3465e4).
Report is 14 commits behind head on main.

Files with missing lines	Patch %	Lines
backend/src/monarch_py/utils/utils.py	86.53%	7 Missing ⚠️

Additional details and impacted files

@@            Coverage Diff             @@
##             main    #1131      +/-   ##
==========================================
+ Coverage   72.05%   72.17%   +0.11%     
==========================================
  Files          92       92              
  Lines        3249     3288      +39     
==========================================
+ Hits         2341     2373      +32     
- Misses        908      915       +7     

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[iQuxLE]

Frontend issue is weird. Its only warnings it should not fail this workflow.

I generated a new model.py with make model. There might have been a new version of pydantic-gen involved, not sure, but somehow the diff in deletions is huge. But seems to all work.