RuntimeExceptions for invalid output configuration doesn't kill the run

[fflaten]

Checklist

• Issue has a meaningful title
• I have searched the existing issues. See all issues
• I have tested using the latest version of Pester. See Installation and update guide.

What is the issue?

When an invalid value is set in output-related configuration options like Output.CIFormat, an exception is called once per failed test/block.

Expected Behavior

Even though the current behavior would allow a successful run to execute, we should move this validation earlier and kill the run as all errors will be unreadable anyways.

Steps To Reproduce

No response

Describe your environment

Pester version : 5.4.0 /workspaces/Pester/bin/Pester.psm1
PowerShell version : 7.2.6
OS version : Unix 5.15.79.1

Possible Solution?

Move validation for output-options to Start-step?