Remove char limitation raw masked vars

What does this MR do and why?

Removes the special character limitation for variables that are masked AND raw (not expanded).

Screenshots or screen recordings

This is under the feature flag ci_remove_character_limitation_raw_masked_var

8 character minimum limitation:

No spaces:

Allowing special characters:

How to set up and validate locally

1. Turn on the feature flag ci_remove_character_limitation_raw_masked_var
2. Add a masked variable and make sure Expanded is unselected
3. Add a value with special characters that is over 8 characters and have no spaces (this is the limitation for this particular value).

MR acceptance checklist

This checklist encourages us to confirm any changes have been analyzed to reduce risks in quality, performance, reliability, security, and maintainability.

• I have evaluated the MR acceptance checklist for this MR.

Resolves: #196871 (closed)