chore: bump sdk and cometbft (backport #8743)

[mergify]

What is the purpose of the change

Bumping cometbft and cosmos sdk to the lastest versions:

comet => https://github.com/osmosis-labs/cometbft/releases/tag/v0.38.12-v26-osmo-2
cosmossdk => https://github.com/osmosis-labs/cosmos-sdk/releases/tag/v0.50.10-v26-osmo-2

---

This is an automatic backport of pull request #8743 done by [Mergify](https://mergify.com).

[mergify]

Cherry-pick of 6f64b71 has failed:

On branch mergify/bp/v26.x/pr-8743
Your branch is up to date with 'origin/v26.x'.

You are currently cherry-picking commit 6f64b711a.
  (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:   CHANGELOG.md
	modified:   osmoutils/go.sum
	modified:   x/epochs/go.mod
	modified:   x/ibc-hooks/go.mod
	modified:   x/ibc-hooks/go.sum

Unmerged paths:
  (use "git add <file>..." to mark resolution)
	both modified:   go.mod
	both modified:   go.sum
	both modified:   osmomath/go.mod
	both modified:   osmomath/go.sum
	both modified:   osmoutils/go.mod
	both modified:   x/epochs/go.sum

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

[github-actions]

Important Notice

This PR modifies an in-repo Go module. It is one of:

• osmomath
• osmoutils
• x/ibc-hooks
• x/epochs

The dependent Go modules, especially the root one, will have to be
updated to reflect the changes. Failing to do so might cause e2e to fail.

Please follow the instructions below:

1. Open https://github.com/osmosis-labs/osmosis/actions/workflows/go-mod-auto-bump.yml
2. Provide the current branch name
3. On success, confirm if an automated commit corretly updated the go.mod and go.sum files

Please let us know if you need any help.