fix: allow type cast of Timestamptz in generated column

[yuhao-su]

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What's changed and what's your intention?

• allow type cast of Timestamptz in generated column.

close #9552

Checklist For Contributors

• I have written necessary rustdoc comments
• I have added necessary unit tests and integration tests
• I have added fuzzing tests or opened an issue to track them. (Optional, recommended for new SQL features Sqlsmith: Sql feature generation #7934).
• I have demonstrated that backward compatibility is not broken by breaking changes and created issues to track deprecated features to be removed in the future. (Please refer to the issue)
• All checks passed in ./risedev check (or alias, ./risedev c)

Checklist For Reviewers

• I have requested macro/micro-benchmarks as this PR can affect performance substantially, and the results are shown.

Documentation

The timezone in generated column

In cases where created generated columns expressions involved a cast that requires timezone (if not explicitly set with AT TIMEZONE):

• When creating a table, the timezone used is the session timezone in the create table session.
• When creating a source, the cast won't be performed. The session timezone in the create source session has no effect
• When creating a MV on source with generated columns expressions involved the cast requires timezone, the timezone used will be the session timezone in the create MV session.

Release note

[codecov]

Codecov Report

Merging #9580 (720f1f8) into main (078ce4f) will increase coverage by 0.00%.
The diff coverage is 100.00%.

@@           Coverage Diff           @@
##             main    #9580   +/-   ##
=======================================
  Coverage   70.73%   70.73%           
=======================================
  Files        1233     1233           
  Lines      206616   206623    +7     
=======================================
+ Hits       146148   146164   +16     
+ Misses      60468    60459    -9     

Flag	Coverage Δ
rust	70.73% <100.00%> (+<0.01%)	⬆️

Flags with carried forward coverage won't be shown. Click here to find out more.

Impacted Files	Coverage Δ
src/frontend/src/handler/create_mv.rs	95.39% <ø> (ø)
src/frontend/src/handler/create_table.rs	90.25% <100.00%> (+0.10%)	⬆️
src/frontend/src/optimizer/mod.rs	92.29% <100.00%> (ø)

... and 8 files with indirect coverage changes

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