sql/catalog/typedesc: fix bug which partially hydrated a type

[ajwerner]

In rare cases where we hit an error hydrating the contained type of an array alias type, we'd populate the name, but not the contents.

Fixes #85376

Release note (bug fix): Fixed a rare bug where errors could occur related to the use of arrays of enums.

[cockroach-teamcity]

This change is 

[ajwerner]

4352 runs so far, 0 failures, over 1h8m15s whereas before it'd always fail within 1000 runs. I feel good about calling this the fix.

[craig[bot]]

Build failed (retrying...):

• Bazel Essential CI (Cockroach)

[craig[bot]]

Build failed (retrying...):

• Bazel Essential CI (Cockroach)

[craig[bot]]

Build succeeded:

• Bazel Essential CI (Cockroach)

[blathers-crl[bot]]

Encountered an error creating backports. Some common things that can go wrong:

1. The backport branch might have already existed.
2. There was a merge conflict.
3. The backport branch contained merge commits.

You might need to create your backport manually using the backport tool.

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error creating merge commit from 6b37080e28773c45b56f5503611683d56ec451eb to blathers/backport-release-21.2-85940: POST https://api.github.com/repos/cockroachdb/cockroach/merges: 409 Merge conflict []

you may need to manually resolve merge conflicts with the backport tool.

Backport to branch 21.2.x failed. See errors above.

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