tfsec issues with 9.2.2

[stevepatter]

Describe the bug

Current (9.2.2) codebase does not fully pass security scans from aquasecurity tfsec (version 1.28.14), with 6 high risk issues identified, 1 medium & 3 low.

These should be resolved, as much as possible, with priority for the high risk issues, I think there'd be a mix of hardcoded parameters & user supplied enable/disable flags to address them

To Reproduce

Steps to reproduce the behavior:

• clone terraform-aws-gitlab-runner repository
• install tfsec
• run tfsec with no additional parameters, it'll generate an output summary

Expected behavior

There should be no high risks reported by tfsec, and ideally no medium or low risk issues.