fix variant space change when pathname equals space-path

[conico974]

If the current page path equals the space path, the SpacesDropdown won't work for this space and you'll stay stuck on this specific space.
In this PR, for these cases, we always set the target url to the root of the other spaces

[linear]

RND-6042 Sometimes switching between variants doesn't work

[github-actions]

Summary of the deployments:

Version 1

Version	URL	Status
Latest commit	https://b3f51c25.gitbook-open.pages.dev	✅
PR	https://pr3343.gitbook-open.pages.dev	✅

Version 2

Version	URL	Status
Vercel	https://gitbook-v2-d533us92x-gitbook.vercel.app	✅
Cloudflare	https://34bea869-gitbook-open-v2-preview.gitbook.workers.dev	✅

Test content

Site	v1	2v	2c
GitBook	https://b3f51c25.gitbook-open.pages.dev/gitbook.com/docs	https://gitbook-v2-d533us92x-gitbook.vercel.app/url/gitbook.com/docs	https://34bea869-gitbook-open-v2-preview.gitbook.workers.dev/url/gitbook.com/docs
E2E	https://b3f51c25.gitbook-open.pages.dev/gitbook.gitbook.io/test-gitbook-open	https://gitbook-v2-d533us92x-gitbook.vercel.app/url/gitbook.gitbook.io/test-gitbook-open	https://34bea869-gitbook-open-v2-preview.gitbook.workers.dev/url/gitbook.gitbook.io/test-gitbook-open

[argos-ci]

The latest updates on your projects. Learn more about Argos notifications ↗︎

Build	Status	Details	Updated (UTC)
customers-v1 (Inspect)	✅ No changes detected	-	Jun 17, 2025, 8:19 PM
customers-v2 (Inspect)	✅ No changes detected	-	Jun 17, 2025, 8:21 PM
default (Inspect)	✅ No changes detected	-	Jun 17, 2025, 8:21 PM
v2-cloudflare (Inspect)	✅ No changes detected	-	Jun 17, 2025, 8:22 PM
v2-vercel (Inspect)	✅ No changes detected	-	Jun 17, 2025, 8:23 PM

[changeset-bot]

⚠️ No Changeset found

Latest commit: 053b3fb

Merging this PR will not cause a version bump for any packages. If these changes should not result in a new version, you're good to go. If these changes should result in a version bump, you need to add a changeset.

This PR includes no changesets

When changesets are added to this PR, you'll see the packages that this PR includes changesets for and the associated semver types

Click here to learn what changesets are, and how to add one.

Click here if you're a maintainer who wants to add a changeset to this PR