Make sure all secrets are secure

[pamelafox]

Purpose

This PR removes security alerts caused by two issues- authClientSecret not being stored in secrets, and secrets not being marked as a secure input in the Bicep.

Does this introduce a breaking change?

[ ] Yes
[X] No

Pull Request Type

What kind of change does this Pull Request introduce?

[X] Bugfix
[ ] Feature
[ ] Code style update (formatting, local variables)
[ ] Refactoring (no functional changes, no api changes)
[ ] Documentation content changes
[ ] Other... Please describe:

How to Test

• Deploy, log in
• Run security scorecard, see no issues for secrets