Missing action prop on group page

What does this MR do?

Currently, when the user tried to leave a group on Subgroups and projects tab, the error is thrown to the console:

This happens because we are listening to the ${this.action}showLeaveGroupModal emitted event on event hub and on the parent component this.action is equal to subgroups-and-projects. However, the action was not passed to the component with the 'Leave' button, so it was emitting an unprefixed showLeaveGroupModal.

This MR adds a correct prop to the child component.

Screenshots (strongly suggested)

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

Related to #296521 (closed)