[backport v2.9.next1] When you choose to customize project/cluster permissions, the UI reports an error when adding project/cluster members

[github-actions[bot]]

This is a backport issue for #10894, automatically created via GitHub Actions workflow initiated by @richard-cox

Original issue body:

Setup

• Rancher version: v2.7.9-v2.8.3
• Rancher UI Extensions: v2.7.9-v2.8.3

Describe the bug

When you choose to customize project/cluseter permissions, the UI reports an error when adding project/cluster members, if Simplified Chinese is selected

To Reproduce

1. Switch UI language to Simplified Chinese: Preferences -> languages-> 简体中文

Add project members

2. Go to the Projects/Namespaces page, and on the project row，click on the Edit Config menu
3. On the member tab page, click the Add button
4. In the Project Permissions section, select Custom Option

Add cluster members

2. Go to the Cluster and Project Members page, and select Cluster Membership tab，click Add button
3. In the Cluster Permissions section, select Custom Option

Result UI goes to error page or UI is not responding

Expected Result

Show project/cluster customization permission options

Screenshots

Additional context

[gaktive]

Focusing on Vue3 migration first, so pushing this out to October.