Update module github.com/aws/smithy-go to v1.20.4

[renovate[bot]]

This PR contains the following updates:

Package	Change	Age	Adoption	Passing	Confidence
github.com/aws/smithy-go	v1.20.3 -> v1.20.4

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Release Notes

aws/smithy-go (github.com/aws/smithy-go)

v1.20.4

Compare Source

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Configuration

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