.NET 8 and NServiceBus.AmazonSQS v7 support

[kentdr]

Describe the suggested improvement

Is your improvement related to a problem? Please describe

Now that NServiceBus Core and AmazonSQS transport have been upgraded to .NET 8, AwsLambda.SQS should follow suit once .NET 8 is supported by AWS Lambda.

Describe the suggested solution

AWS Lambda currently supports .NET 6, so this library has to continue referencing v6 of NServiceBus.AmazonSQS until support for .NET 8 is added.

Once AWS Lambda officially supports .NET 8, update AWSLambda.SQS to the latest NServiceBus.AmazonSQS transport version.

See this draft PR that bumps NServiceBus.AWSLambda.SQS to the latest v7 of NServiceBus.AmazonSQS.

Describe alternatives you've considered

A custom runtime could be implemented to support .NET 8 sooner. We anticipate Lambda to have official support for .NET 8 since it is an LTS release and believe this option to be not worth the effort.

Additional Context

Tracking issue