.github/workflows: disable scheduled trivy scans

[sam-heilbron]

Description

Disable trivy scanner from running

Context

This job is tightly coupled to Solo.io infrastructure (Slack). Currently it reports errors erroneously, so we should disable the job.

Interesting decisions

Testing steps

Notes for reviewers

Checklist:

• I have performed a self-review of my own code
• I have commented my code, particularly in hard-to-understand areas
• I have made corresponding changes to the documentation
• I have added tests that prove my fix is effective or that my feature works

[sam-heilbron]

/skip-changelog non-functional

[nfuden]

Thanks for the contribution. Do you think we can just delete the slack piece and then have issues opened in this repo?