Add autocomplete off to text inputs

What does this MR do and why?

Adds autocomplete off to the vulnerability form inputs.

Screenshots or screen recordings

before	after

How to set up and validate locally

1. You'll need an EE license.
2. Navigate to :namespace/:project/-/security/vulnerabilities/new using the Address bar
3. Fill the form and click submit
4. Come back to the vulnerability form
5. Refill the form, you should see no autocompletion

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.

Related to #352128 (closed)