Run docker image as non-root user

[pmachapman]

Fix #984.

I'm not sure about the kubernetes config, as I have no real way of testing it. It passed a lint, and matched the guidance from Microsoft, but is untested.

Documentation:

• https://devblogs.microsoft.com/dotnet/securing-containers-with-rootless/
• https://devblogs.microsoft.com/dotnet/running-nonroot-kubernetes-with-dotnet/

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This change is 

[codecov-commenter]

Codecov Report

✅ All modified and coverable lines are covered by tests.
✅ Project coverage is 72.59%. Comparing base (43ffd54) to head (4ed0efd).

Additional details and impacted files

@@           Coverage Diff           @@
##             main    #1036   +/-   ##
=======================================
  Coverage   72.59%   72.59%           
=======================================
  Files         391      391           
  Lines       21676    21676           
  Branches     2820     2820           
=======================================
  Hits        15735    15735           
  Misses       4814     4814           
  Partials     1127     1127           

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[Enkidu93]

@pmachapman You could test this on internal QA?