fix: ensure information_schema default values for identity columns without explicit sequence options

[andrew-delph]

This commit addresses the issue where identity columns created without explicit sequence options lacked
default values in the information_schema. The changes ensure that identity columns have default identity attributes, aligning with the expected behavior when sequence options are specified.

Epic: None
Release note (bug fix): Identity columns without
specified sequence options now correctly show default values for identity attributes in information_schema.

[blathers-crl]

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[cockroach-teamcity]

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[blathers-crl]

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[andrew-delph]

After taking another look at this, I'm not sure if its making some code here redundant.
https://github.com/cockroachdb/cockroach/blob/master/pkg/sql/catalog/tabledesc/column.go#L267

And also in this place, where I didn't include a change.
https://github.com/cockroachdb/cockroach/blob/master/pkg/sql/information_schema.go#L538
Possibly It could assert because its no longer possible.

[rafiss]

nice fix! thank you

bors r+

Reviewed 2 of 2 files at r1, all commit messages.
Reviewable status: complete! 0 of 0 LGTMs obtained (waiting on @annrpom)

[craig]

Build succeeded:

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• docker_image_amd64
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