Fix Dismiss checkbox on Security Dashboard
### Summary
When there are no found vulnerabilities, the checkbox for dismissing vulnerabilities is still visible.
### Steps to reproduce
1. Go to Project Security Dashboard
1. Select Report type when there are no findings.
1. Observe checkbox that bulk dismisses vulnerabilities which isn't hidden.
### Example Project
https://gitlab.com/gitlab-org/gitlab/-/security/dashboard
### What is the current *bug* behavior?
The checkbox is visible and selected.
### What is the expected *correct* behavior?
The checkbox should be visible but not selected. The checkbox should never be in a selected state unless a user has intentionally selected it.
### Relevant logs and/or screenshots

### Possible fixes
TBA
/cc @lkerr
issue