Update Warning Received when you setup PublicNetworkAccess

# Description
## Actual Behavior
1. I'm looking to deploy over ARM/Bicep/Terraform a Relay with the property Public Network Access configured
2. As per the documentation this property should be done into the Namespace level (https://learn.microsoft.com/en-us/azure/templates/microsoft.relay/namespaces?pivots=deployment-language-bicep)
3. After working on this we've identified this property should be configured over the Network Rule Sets
4. When you setup the Public Network Access property under Network Rule Sets you are getting the next Warning
`> az deployment group create --resource-group relay-jdobla --template-file relay_module.bicep
/home/jose/folder/relay_module.bicep(47,4) : Warning BCP037: The property "publicNetworkAccess" is not allowed on objects of type "NetworkRuleSetProperties". No other properties are allowed. If this is an inaccuracy in the documentation, please report it to the Bicep Team. [https://aka.ms/bicep-type-issues]
/home/jose/folder/relay_module.bicep(50,5) : Warning no-unnecessary-dependson: Remove unnecessary dependsOn entry 'relay'.`

5. If you press enter the Relay will be created with the property correctly setup
6. There is currently a PR opened to modify this document: https://github.com/Azure/azure-rest-api-specs/pull/20745

## Expected Behavior
1. Deploy the Relay with the Public Network Access configured under the Network Rule Sets without receiving the next warning
`https://github.com/Azure/azure-rest-api-specs/pull/20745`