Update Azure SDK for .NET logging guidance

[scottaddie]

Update the Logging without client registration section once the new AddAzureClientsCore overload is added via https://github.com/Azure/azure-sdk-for-net/issues/30105.

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Document Details

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• ID: 337e8ed0-9a24-93ce-c7cf-478c0e24dc06
• Version Independent ID: 2151de27-a308-a249-277d-7addb659775e
• Content: Logging with the Azure SDK for .NET
• Content Source: docs/azure/sdk/logging.md
• Product: dotnet-azure
• GitHub Login: @CamSoper
• Microsoft Alias: casoper