test(x/gamm): remove liquidity events (backport #2186)

[mergify]

This is an automatic backport of pull request #2186 done by Mergify.
Cherry-pick of 40f19a3 has failed:

On branch mergify/bp/v11.x/pr-2186
Your branch is up to date with 'origin/v11.x'.

You are currently cherry-picking commit 40f19a38.
  (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:
	new file:   app/apptesting/events.go
	modified:   x/gamm/keeper/internal/events/emit_test.go
	modified:   x/gamm/keeper/msg_server.go
	modified:   x/gamm/keeper/msg_server_test.go
	modified:   x/gamm/keeper/swap_test.go
	modified:   x/gamm/spec/README.md

Unmerged paths:
  (use "git add <file>..." to mark resolution)
	both modified:   CHANGELOG.md
	both modified:   x/gamm/keeper/pool_service_test.go
	both modified:   x/superfluid/keeper/unpool_test.go

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

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