chore(ci): Remove Semgrep GHA Workflow

[eduardoboronat-okta]

Semgrep is Okta's static application security testing tool. It was previously recommended to add Semgrep directly into CI/CD pipelines or workflows. However, the ProdSec team has enhanced the tooling, and Semgrep scanning is now built into the platform via a GitHub Application.

ℹ️ Details

• You'll find all of your PRs are already being scanned by a dedicated Semgrep step. Given this, you no longer need to run Semgrep via a Github Action workflow.
• ⚠️ This PR attempts to help remove it for you. Please review this change carefully to ensure it doesn't impact any other jobs. Any adjustments needed to make this PR pass is the responsibility of the owners of the repository. (You are also welcome to close this PR and remove Semgrep CI separately).

Created by Sourcegraph batch change eduardo.boronat/Remove-Semgrep-GHA-non-EMU.

[codecov-commenter]

Codecov Report

✅ All modified and coverable lines are covered by tests.
✅ Project coverage is 99.85%. Comparing base (5b556ac) to head (f25dd79).
⚠️ Report is 1 commits behind head on main.

Additional details and impacted files

@@            Coverage Diff            @@
##               main     #796   +/-   ##
=========================================
  Coverage     99.85%   99.85%           
  Complexity     1428     1428           
=========================================
  Files            65       65           
  Lines          4996     4996           
=========================================
  Hits           4989     4989           
  Misses            7        7           

Flag	Coverage Δ
unittestsvalidate	99.85% <ø> (ø)

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[kishore7snehil]

This has been release as part of 8.16.0.