Removed confirmation modal when dismissing onboarding (#19979)

closes https://linear.app/tryghost/issue/IPC-138/skip-onboarding-confirmation

- removed confirmation modal
- changed button to directly call the dismiss action on the onboarding service

ghost/admin/app/components/dashboard/onboarding-checklist.hbs

@@ -75,6 +75,6 @@
     <p class="gh-onboarding-help">More questions? Check out our <a href="https://ghost.org/help?utm_source=admin&utm_campaign=onboarding" target="_blank" rel="noopener noreferrer">Help Center</a>.</p>
 
     {{#unless this.onboarding.allStepsCompleted}}
-        <a href="#" class="gh-onboarding-skip" {{on "click" this.confirmDismiss}}>Skip onboarding</a>
+        <a href="#" class="gh-onboarding-skip" {{on "click" this.onboarding.dismissChecklist}}>Skip onboarding</a>
     {{/unless}}
 </div>

ghost/admin/app/components/dashboard/onboarding-checklist.js

@@ -1,5 +1,4 @@
 import Component from '@glimmer/component';
-import DismissModal from './onboarding/dismiss-modal';
 import ShareModal from './onboarding/share-modal';
 import {action} from '@ember/object';
 import {inject} from 'ghost-admin/decorators/inject';
@@ -11,7 +10,6 @@ export default class OnboardingChecklist extends Component {
 
     @inject config;
 
-    dismissModal = null;
     shareModal = null;
 
     willDestroy() {
@@ -29,17 +27,4 @@ export default class OnboardingChecklist extends Component {
         this.onboarding.markStepCompleted('share-publication');
         this.shareModal = this.modals.open(ShareModal);
     }
-
-    @action
-    async confirmDismiss() {
-        this.dismissModal = this.modals.open(DismissModal, {}, {backgroundBlur: true});
-
-        const reallyDismiss = await this.dismissModal;
-
-        if (reallyDismiss === true) {
-            this.onboarding.dismissChecklist();
-        } else {
-            this.dismissModal = null;
-        }
-    }
 }

ghost/admin/app/components/dashboard/onboarding/dismiss-modal.hbs

@@ -1,19 +0,0 @@
-<div class="modal-content">
-    <header class="modal-header">
-        <h1>Are you sure you want to skip onboarding?</h1>
-    </header>
-    <button class="close" title="Close" type="button" {{on "click" @close}}>{{svg-jar "close"}}<span
-            class="hidden">Close</span></button>
-
-    <div class="modal-body">
-        <p>
-            We're here to guide you every step of the way, but if you're ready
-            to explore on your own, that's okay, too.
-        </p>
-    </div>
-
-    <div class="modal-footer">
-        <button class="gh-btn" type="button" {{on "click" @close}}><span>Cancel</span></button>
-        <button class="gh-btn gh-btn-black" type="button" {{on "click" (fn @close true)}}><span>Skip onboarding</span></button>
-    </div>
-</div>