Remove uncessary type parameter and constraints from Upgrade service

[hlbarber]

Motivation and Context

The type parameter B was not only redundant but also removed a degree of freedom from the API.

Description

• Remove type parameter B from Upgrade and related code.
• Remove repeated constraint on the upgraded service.

[github-actions]

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• AWS SDK (ignoring whitespace)
• No codegen difference in the Client Test
• No codegen difference in the Server Test
• No codegen difference in the Server Test Python

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[jjant]

• Why was this type variable there in the first place?
• Will we be removing any of the other phantom type variables in Upgrade later?

You might want to update these docs (they seem to have an outdated version of Upgrade with only 3 tyvars).

[hlbarber]

Why was this type variable there in the first place?

Just a mistake - I'm guessing I was mucking around with types and it was required in a previous iteration.

Will we be removing any of the other phantom type variables in Upgrade later?

It's a possibility, this PR was motivated by a specific excess constraint. A more general investigation can be performed and might reveal some extra redundancy.

You might want to update these docs (they seem to have an outdated version of Upgrade with only 3 tyvars).

This was intentional to simplify the documentation. There do seems to be some references to B here that can be removed though - I'll update it.

[github-actions]

A new generated diff is ready to view.

• AWS SDK (ignoring whitespace)
• No codegen difference in the Client Test
• No codegen difference in the Server Test
• No codegen difference in the Server Test Python

A new doc preview is ready to view.

[github-actions]

A new generated diff is ready to view.

• AWS SDK (ignoring whitespace)
• No codegen difference in the Client Test
• No codegen difference in the Server Test
• No codegen difference in the Server Test Python

A new doc preview is ready to view.