fix: pricing table links to wrong page in docs (p2) (#7434)

## Summary

Continuation of updating pricing table link (p1 was
https://github.com/Comfy-Org/ComfyUI_frontend/pull/7402). Create a
constant since it's now used in multiple locations.

┆Issue is synchronized with this [Notion
page](https://www.notion.so/PR-7434-fix-pricing-table-links-to-wrong-page-in-docs-p2-2c86d73d36508199b320d49faa6a0c73)
by [Unito](https://www.unito.io)

src/components/topbar/CurrentUserPopover.test.ts

@@ -131,7 +131,10 @@ vi.mock('@/base/credits/comfyCredits', () => ({
 // Mock useExternalLink
 vi.mock('@/composables/useExternalLink', () => ({
   useExternalLink: vi.fn(() => ({
-    buildDocsUrl: vi.fn((path) => `https://docs.comfy.org${path}`)
+    buildDocsUrl: vi.fn((path) => `https://docs.comfy.org${path}`),
+    docsPaths: {
+      partnerNodesPricing: '/tutorials/partner-nodes/pricing'
+    }
   }))
 }))