[Validator] add deprecation log (#12674)
minor #12730 add deprecation log (#12674) (phramz)

This PR was merged into the 2.7 branch.

Discussion
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add deprecation log (#12674)

| Q             | A
| ------------- | ---
| Bug fix?      | no
| New feature?  | no
| BC breaks?    | no
| Deprecations? | yes
| Tests pass?   | yes
| Fixed tickets | #12674
| License       | MIT
| Doc PR        |

Commits
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2e47b62 [Validator] add deprecation log (#12674)