Clean up some jackson dependency excludes by moving it to top level pom

[capistrant]

Description

follow on to #18013. It was pointed out, after merge, that I should have consolidated the excludes for two of the jackson libraries in the root pom instead of adding one off to every module that needed it. This aims to rectify that mistake. It also found another location where comments called for removing an explicit snakeyaml version pin in a module once jackson got upgraded.

Release note

N/A

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Key changed/added classes in this PR

• pom.xml

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This PR has:

• been self-reviewed.
• added documentation for new or modified features or behaviors.
• a release note entry in the PR description.
• added Javadocs for most classes and all non-trivial methods. Linked related entities via Javadoc links.
• added or updated version, license, or notice information in licenses.yaml
• added comments explaining the "why" and the intent of the code wherever would not be obvious for an unfamiliar reader.
• added unit tests or modified existing tests to cover new code paths, ensuring the threshold for code coverage is met.
• added integration tests.
• been tested in a test Druid cluster.

[kfaraz]

LGTM 👍🏻