AddMemberDialog remove footer styling from old component (#63)

### TL;DR

This PR involves a minor change on the AddMemberDialog component style.

### What changed?

The 'justify-start' class was removed from the Modal.Footer in the AddMemberDialog.tsx.

### How to test?

Check the AddMemberDialog on the project settings page to make sure the style changes reflect accurately.

### Why make this change?

It's not specified the specific reason for the change, However, it's aimed towards improving the component's layout and presentation in the project settings page.

---

packages/frontend/src/components/projects/project/settings/AddMemberDialog.tsx

@@ -87,7 +87,7 @@ const AddMemberDialog = ({
               color="blue"
             />
           </Modal.Body>
-          <Modal.Footer className="flex justify-start">
+          <Modal.Footer>
             <Button onClick={handleOpen} variant="secondary">
               Cancel
             </Button>