Fix state not being updated

What does this MR do?

Fixes a bug that occurs when:

1. User selects multiple vulnerabilities to dismiss them (under any filter active - for instance resolved)
2. Some of them fails because of any reason
3. State is not updated accordingly

In order to reproduce this checkout this branch and change the following line:

const promises = this.selectedVulnerabilities.map(vulnerability =>
 this.$apollo.mutate({
   mutation: dismissVulnerability,
   variables: { id: vulnerability.id, comment: this.dismissalReason },
 }),
);

to

const promises = this.selectedVulnerabilities.map((vulnerability, i) =>
  this.$apollo.mutate({
    mutation: dismissVulnerability,
    variables: { id: i % 2 ? 10000 : vulnerability.id, comment: this.dismissalReason },
  }),
);

in

ee/app/assets/javascripts/security_dashboard/components/selection_summary.vue:59

To fix this, I had to emit the refetch-vulnerabilities also when the requests fail and the parent component removes the no longer existing vulnerabilities from selectedVulnerabilities.

Screenshots

Does this MR meet the acceptance criteria?

Conformity

• Changelog entry
• Documentation (if required)
• Code review guidelines
• Merge request performance guidelines
• Style guides
• Database guides
• Separation of EE specific content

Availability and Testing

• Review and add/update tests for this feature/bug. Consider all test levels. See the Test Planning Process.
• Tested in all supported browsers
• Informed Infrastructure department of a default or new setting change, if applicable per definition of done

Security

If this MR contains changes to processing or storing of credentials or tokens, authorization and authentication methods and other items described in the security review guidelines:

• Label as security and @ mention @gitlab-com/gl-security/appsec
• The MR includes necessary changes to maintain consistency between UI, API, email, or other methods
• Security reports checked/validated by a reviewer from the AppSec team