fix(xo-web/kubernetes): remove required property from search domain

[ggunullu]

To merge alongside with https://gitlab.com/vates/xoa/-/merge_requests/130

Description

Short explanation of this PR (feel free to re-use commit message)

Checklist

• Commit
  • Title follows commit conventions
  • Reference the relevant issue (Fixes #007, See xoa-support#42, See https://...)
  • If bug fix, add Introduced by
• Changelog
  • If visible by XOA users, add changelog entry
  • Update "Packages to release" in CHANGELOG.unreleased.md
• PR
  • If UI changes, add screenshots
  • If not finished or not tested, open as Draft

[julien-f]

Is it working correctly?

What is sent to the server if the field is empty?

[ggunullu]

Is it working correctly?

What is sent to the server if the field is empty?

Yes, it works correctly.

undefined is sent to the server if the field is empty. Actually, on the server side, this parameter was already optional if the user chose dynamic network configuration for the cluster.

[julien-f]

@ggunullu Are you sure? What if the user types in the field and then clears it?

[ggunullu]

@ggunullu Are you sure? What if the user types in the field and then clears it?

You're right it wouldn't work, I hadn't thought about this scenario. I'll correct that.