Make dc.type required

[pnbecker]

fixes #9357

Description

Make dc.type required as discussed in dev meeting and in #9357

Checklist

• My PR is small in size (e.g. less than 1,000 lines of code, not including comments & integration tests). Exceptions may be made if previously agreed upon.
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[tdonohue]

👍 Thanks @pnbecker ! This looks good to me and it can be merged once the backend upgrades are completed in #9321

I've also looked at the failing IT and I can verify this test was refactored in #9321 because I found it was "flakey". So, this failing IT is unrelated to this PR, and I believe it will be "fixed" once #9321 is merged.