chore(upgrade): clean up handler and typo

[julienrbrt]

Description

IBC team pointed that we deleted the gov router handler for distribution community pool fund proposal as soon as we had a message for it (https://github.com/cosmos/cosmos-sdk/pull/12852/files#diff-30401ffe994c39331e8d8cab70fc2dd985af611922e62b6eb4d3f472d5f80ed3)
We've updated the upgrade cli to use gov v1 in #14880.
For consistency, we should delete it as well. Then we only have params left (which we won't be able to remove anyway).
gov v1beta1 proposals are still supported anyway.

---

Author Checklist

All items are required. Please add a note to the item if the item is not applicable and
please add links to any relevant follow up issues.

I have...

• included the correct type prefix in the PR title
• added ! to the type prefix if API or client breaking change
• targeted the correct branch (see PR Targeting)
• provided a link to the relevant issue or specification
• followed the guidelines for building modules
• included the necessary unit and integration tests
• added a changelog entry to CHANGELOG.md
• included comments for documenting Go code
• updated the relevant documentation or specification
• reviewed "Files changed" and left comments if necessary
• confirmed all CI checks have passed

Reviewers Checklist

All items are required. Please add a note if the item is not applicable and please add
your handle next to the items reviewed if you only reviewed selected items.

I have...

• confirmed the correct type prefix in the PR title
• confirmed ! in the type prefix if API or client breaking change
• confirmed all author checklist items have been addressed
• reviewed state machine logic
• reviewed API design and naming
• reviewed documentation is accurate
• reviewed tests and test coverage
• manually tested (if applicable)