[SECURITY] RESOPS134 - Secret Scanning workflow

[TobySMurray]

Description

This adds a workflow using trufflehog to scan for secrets that have been accidentally pushed in a commit.

Closes #134

How to Test

Push code to a branch, workflow will run

Checklist

• [x] The code includes tests if relevant
• [x] I have actually self-reviewed my changes and done QA