Is there an existing issue for this?

• I have searched the existing issues

Current Behavior

Create Workspace is greyed out, despite the workspace name, owner and external auth being completed.

from @jaaydenh:

the top level diagnostics error in this case is not being displayed because parameters are null.

Relevant Log Output

{
    "id": -1,
    "diagnostics": [
        {
            "severity": "error",
            "summary": "Panic occurred in preview. This should not happen, please report this to Coder.",
            "detail": "panic in preview: unable to load resources to context: unsupported index type string",
            "extra": {
                "code": ""
            }
        }
    ],
    "parameters": null
}

Expected Behavior

Create Workspace should be clickable.

Steps to Reproduce

Internal repro steps:

1. Login to dev.coder.com
2. Create workspace from Write Coder on Coder using Envbuilder template
3. Navigate to new creation flow
4. Input workspace name & authenticate to GitHub

Environment

• Host OS:
• Coder version: v2.22.1-devel+818d4d03f

Additional Context

No response