fix: hashing of scanners in scan id

[didroe]

Description

Fixes hashing of scanners (eg. sast, secrets) when building a scan id. The scan id is the key used for caching reports.

Previously, we were including an empty list of scanners each time. This meant that cached reports for one scanner option were being used when a different option was given.

Checklist

• I've added test coverage that shows my fix or feature works as expected.
• I've updated or added documentation if required.
• I've included usage information in the description if CLI behavior was updated or added.
• PR title follows Conventional Commits format