bypasses OIDC auth flow for admin user in cli usage

[ianseyer]

Thank you for contributing to Harbor!

Comprehensive Summary of your change

This PR bypasses OIDC auth flow for admin user (when OIDC is enabled), similar to how robot users are bypassed (see below PR)

Issue being fixed

Fixes #15253 ; partial fix done here: #18317

Please indicate you've done the following:

• Well Written Title and Summary of the PR
• Label the PR as needed. "release-note/ignore-for-release, release-note/new-feature, release-note/update, release-note/enhancement, release-note/community, release-note/breaking-change, release-note/docs, release-note/infra, release-note/deprecation"
• Accepted the DCO. Commits without the DCO will delay acceptance.
• Made sure tests are passing and test coverage is added if needed.
• Considered the docs impact and opened a new docs issue or PR with docs changes if needed in website repository.

[codecov]

Codecov Report

Attention: Patch coverage is 0% with 1 line in your changes missing coverage. Please review.

Project coverage is 66.07%. Comparing base (c8c11b4) to head (92dc646).
Report is 300 commits behind head on main.

Files with missing lines	Patch %	Lines
src/server/middleware/security/oidc_cli.go	0.00%	0 Missing and 1 partial ⚠️

Additional details and impacted files

@@             Coverage Diff             @@
##             main   #21073       +/-   ##
===========================================
+ Coverage   45.36%   66.07%   +20.71%     
===========================================
  Files         244     1049      +805     
  Lines       13333   114645   +101312     
  Branches     2719     2867      +148     
===========================================
+ Hits         6049    75757    +69708     
- Misses       6983    34746    +27763     
- Partials      301     4142     +3841     

Flag	Coverage Δ
unittests	66.07% <0.00%> (+20.71%)	⬆️

Flags with carried forward coverage won't be shown. Click here to find out more.

Files with missing lines	Coverage Δ
src/server/middleware/security/oidc_cli.go	67.30% <0.00%> (ø)

... and 1287 files with indirect coverage changes

[ianseyer]

work covered in #21061