Edit Workloads: Container tabs merge when adding a new container

[yonasberhe23]

Setup

• Rancher version: v2.12 ... v2.8

Describe the bug
When adding a container on the Pods edit page, the page renders incorrectly (e.g. both container 0 and container 1 are under the same tab).

To Reproduce

1. go to a Cluster => Workloads => Pods => Create
2. go to Pod's detail view => click Config
3. click the ellipsis => Edit config
4. on the Edit page click the '+ Add Container' tab
5. scroll the page
6. notice both container 0 and container 1 are under the same tab

Result
When adding a container on the Pods edit page, both container 0 and container 1 are under the same tab.

Expected Result
When adding a container on the Pods edit page, the container 0 tab remains, and container 1 is added in a separate tab.

Screenshots

Screen.Recording.2025-04-15.at.10.54.59.AM.mov

Additional context
Discovered while testing: #13958

[rak-phillip]

To add context, this only happens when first viewing the config before clicking on edit. Navigating directly to "Edit Config" does not exhibit this behavior. Also, unlike #13958, this affects all workload forms instead of only Pods.