Azure EventHubs Emulator WithDataBindMount doesn't do anything

[eerhardt]

We have WithDataBindMount and WithDataVolume on the EventHubs emulator:

aspire/src/Aspire.Hosting.Azure.EventHubs/AzureEventHubsExtensions.cs

Lines 366 to 390 in 3b08e15

	/// <summary>
	/// Adds a bind mount for the data folder to an Azure Event Hubs emulator resource.
	/// </summary>
	/// <param name="builder">The builder for the <see cref="AzureEventHubsEmulatorResource"/>.</param>
	/// <param name="path">Relative path to the AppHost where emulator storage is persisted between runs. Defaults to the path '.eventhubs/{builder.Resource.Name}'</param>
	/// <returns>A builder for the <see cref="AzureEventHubsEmulatorResource"/>.</returns>
	public static IResourceBuilder<AzureEventHubsEmulatorResource> WithDataBindMount(this IResourceBuilder<AzureEventHubsEmulatorResource> builder, string? path = null)
	{
	ArgumentNullException.ThrowIfNull(builder);
	return builder.WithBindMount(path ?? $".eventhubs/{builder.Resource.Name}", "/data", isReadOnly: false);
	}
	/// <summary>
	/// Adds a named volume for the data folder to an Azure Event Hubs emulator resource.
	/// </summary>
	/// <param name="builder">The builder for the <see cref="AzureEventHubsEmulatorResource"/>.</param>
	/// <param name="name">The name of the volume. Defaults to an auto-generated name based on the application and resource names.</param>
	/// <returns>A builder for the <see cref="AzureEventHubsEmulatorResource"/>.</returns>
	public static IResourceBuilder<AzureEventHubsEmulatorResource> WithDataVolume(this IResourceBuilder<AzureEventHubsEmulatorResource> builder, string? name = null)
	{
	ArgumentNullException.ThrowIfNull(builder);
	return builder.WithVolume(name ?? VolumeNameGenerator.Generate(builder, "data"), "/data", isReadOnly: false);
	}

However, it appears that this folder isn't where the EventHubs emulator writes persistent data to. Looking at the docs:

https://learn.microsoft.com/en-us/azure/event-hubs/overview-emulator#known-limitations

Note
After a container restart, data and entities don't persist in the emulator.

We should obsolete these methods if they don't enable a scenario.

See https://github.com/dotnet/aspire/pull/4209/files#r1619294488 for some discussion on this topic.

cc @sebastienros @oising