[cloudtest] Use correct union types for sql execute statements

[rjobanp]

Motivation

This swaps the LiteralString type annotation to the Query type union defined by psycopg so I can use the psycopg sql.SQL type in a DDL statement where I can't use a LiteralString. See https://www.psycopg.org/psycopg3/docs/advanced/typing.html#checking-literal-strings-in-queries for details

I also switched the Sequence[Any] annotations to use the psycopg Params union-type to future-proof that.

sql_query and sql_execute still annotate their query parameter as str, which is actually incorrect with the move to psycopg 3.. I can update those too but I was wondering if there was a reason to leave them as-is. LMK your thoughts.

Tips for reviewer

Checklist

• This PR has adequate test coverage / QA involvement has been duly considered.
• This PR has an associated up-to-date design doc, is a design doc (template), or is sufficiently small to not require a design.
• If this PR evolves an existing $T ⇔ Proto$T mapping (possibly in a backwards-incompatible way), then it is tagged with a T-proto label.
• If this PR will require changes to cloud orchestration or tests, there is a companion cloud PR to account for those changes that is tagged with the release-blocker label (example).
• This PR includes the following user-facing behavior changes:

[nrainer-materialize]

sql_query and sql_execute still annotate their query parameter as str, which is actually incorrect with the move to psycopg 3.. I can update those too but I was wondering if there was a reason to leave them as-is. LMK your thoughts.

Yes, I think we should update them too. I think the .encode("utf8") did the trick so far but no reason to keep that.

[nrainer-materialize]

Thank you!

[necaris]

Yes, I think we should update them too. I think the .encode("utf8") did the trick so far but no reason to keep that.

Right -- encoding them as utf-8 marks it as bytes so it's part of the union type, which is... OK but not amazing.

[rjobanp]

Great thanks for the input - I've updated all the methods now.