Remove the read_capacity and write_capacity from lifecycle change ignore

[virgofx]

The DynamoDB resource recommends using lifecycle ignores for read and write capacity values when using autoscaling. However, since we're not using autoscaling here, it makes it impossible to update DynamoDB read/write capacity changes after the table has been created in follow up operations.

So either, remove these parameters from the lifecycle/ignore_changes or variablize them such that consumers can opt to not use autoscaling and explicitly set these.