[BUG] Dashboard name's regular expression is too strict

### API Spec link

https://github.com/Azure/azure-rest-api-specs/blob/b9e65c8997ce097af3f773a48d2ea2e0535f3cca/specification/portal/resource-manager/Microsoft.Portal/preview/2022-12-01-preview/portal.json#L185-L192

### API Spec version

2022-12-01-preview

### Describe the bug

Portal Dashboard's Name has a regular expression `"pattern": "^[a-zA-Z0-9-]{3,24}$"` which defines the maximum length to 24. This is wrong in practice: longer names are allowed. The same property has `"maxLength": 64,` on it, while [Bicep docs](https://learn.microsoft.com/en-us/azure/templates/microsoft.portal/dashboards?pivots=deployment-language-bicep#dashboards) say the max length is 160.

Regression was introduced in https://github.com/Azure/azure-rest-api-specs/pull/29796

### Expected behavior

"pattern": "^[a-zA-Z0-9-]{3,160}$"

### Actual behavior

"pattern": "^[a-zA-Z0-9-]{3,24}$"

### Reproduction Steps

It's about the Open API spec being wrong.

### Environment

_No response_