Add security context to task execution metadata

[noahjax]

Tracking issue

https://github.com/flyteorg/flyte/issues/

Why are the changes needed?

For our specific use case it is critical to be able to determine the identity for the subject who launches a task. It seems like other information on the security context could also be more generally useful, so I included that in addition to the critical execution_identity field as part of this PR.

What changes were proposed in this pull request?

Add securityContext to TaskExecutionMetadata. This builds on top of conjunction with https://github.com/flyteorg/flytekit/pull/2282, and relies on https://github.com/flyteorg/flyte/pull/5105 to add security context to the flyteidl TaskExecutionMetadata.

How was this patch tested?

Setup process

Screenshots

Check all the applicable boxes

• [ ] I updated the documentation accordingly.
• [ ] All new and existing tests passed.
• [ ] All commits are signed-off.

Related PRs

Docs link

[codecov[bot]]

Codecov Report

Attention: Patch coverage is 80.00000% with 1 lines in your changes are missing coverage. Please review.

Project coverage is 82.33%. Comparing base (133e8d5) to head (72c1903). Report is 4 commits behind head on master.

Files	Patch %	Lines
flytekit/models/task.py	75.00%	1 Missing :warning:

Additional details and impacted files

@@            Coverage Diff             @@
##           master    #2296      +/-   ##
==========================================
- Coverage   83.50%   82.33%   -1.18%     
==========================================
  Files         324      324              
  Lines       24672    24677       +5     
  Branches     3512     3513       +1     
==========================================
- Hits        20603    20318     -285     
- Misses       3438     3721     +283     
- Partials      631      638       +7     

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[noahjax]

Closed in favor of https://github.com/flyteorg/flytekit/pull/2315