chore: optimize checkTx (backport #3954)

[mergify]

Overview

this PR makes a simple optimization for checkTx

---

This is an automatic backport of pull request #3954 done by [Mergify](https://mergify.com).

[mergify]

Cherry-pick of ca222a8 has failed:

On branch mergify/bp/v2.x/pr-3954
Your branch is up to date with 'origin/v2.x'.

You are currently cherry-picking commit ca222a86.
  (fix conflicts and run "git cherry-pick --continue")
  (use "git cherry-pick --skip" to skip this patch)
  (use "git cherry-pick --abort" to cancel the cherry-pick operation)

Changes to be committed:
	modified:   app/process_proposal.go
	modified:   app/test/prepare_proposal_test.go
	modified:   app/validate_txs.go
	modified:   x/blob/ante/blob_share_decorator.go

Unmerged paths:
  (use "git add <file>..." to mark resolution)
	both modified:   app/test/process_proposal_test.go
	both modified:   x/blob/ante/blob_share_decorator_test.go

To fix up this pull request, you can check it out locally. See documentation: https://docs.github.com/en/pull-requests/collaborating-with-pull-requests/reviewing-changes-in-pull-requests/checking-out-pull-requests-locally

[rootulp]

I'll wait for @evan-forbes 's approval b/c I made a few very minor changes to the original PR

[cmwaters]

👍