Set correct type annotations for ColumnElement.cast

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Fixes: #9156

### Description
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### Checklist
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This pull request is:

- [ ] A documentation / typographical error fix
	- Good to go, no issue or tests are needed
- [x] A short code fix
	- please include the issue number, and create an issue if none exists, which
	  must include a complete example of the issue.  one line code fixes without an
	  issue and demonstration will not be accepted.
	- Please include: `Fixes: #<issue number>` in the commit message
	- please include tests.   one line code fixes without tests will not be accepted.
- [ ] A new feature implementation
	- please include the issue number, and create an issue if none exists, which must
	  include a complete example of how the feature would look.
	- Please include: `Fixes: #<issue number>` in the commit message
	- please include tests.

**Have a nice day!**

Closes: #9157
Pull-request: https://github.com/sqlalchemy/sqlalchemy/pull/9157
Pull-request-sha: 321dac184ee0d317296a689d7c8e47bf1464bcce

Change-Id: I99fe759a21de910f34bae3bb919e82cd08969e81

0 files changed, 0 insertions, 0 deletions