[ResourceNameRestriction] Should enums (without "pattern") be treated as valid or invalid?

**Describe the bug**
https://github.com/Azure/azure-rest-api-specs/pull/22978/checks?check_run_id=13024521883

> The resource name parameter 'notificationName' should be defined with a 'pattern' restriction.
> Location: [Microsoft.ApiManagement/preview/2022-09-01-preview/apimworkspaces.json#L1828](https://github.com/Azure/azure-rest-api-specs/blob/e6e61df03b325344f43cdfe756c44ed58d94e409/specification/apimanagement/resource-manager/Microsoft.ApiManagement/preview/2022-09-01-preview/apimworkspaces.json#L1828)

The parameter already has restriction as defined here

https://github.com/Azure/azure-rest-api-specs/blob/e6e61df03b325344f43cdfe756c44ed58d94e409/specification/apimanagement/resource-manager/Microsoft.ApiManagement/preview/2022-09-01-preview/apimanagement.json#L467

**To Reproduce**
Steps to reproduce the behavior:

**Expected behavior**
A clear and concise description of what you expected to happen.

**Screenshots**
If applicable, add screenshots to help explain your problem.

**Desktop (please complete the following information):**
- OS: [e.g. iOS]
- Browser [e.g. chrome, safari]
- Version [e.g. 22]

**Additional context**
Details in https://github.com/Azure/azure-rest-api-specs/issues/23737