fix: remove duplicated app.Close call

[yihuang]

Description

the app.Close is called in the appCleanupFunc, so no need to call in other places.

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[facundomedica]

LGTM, notes for other reviewers:

cosmos-sdk/server/start.go

Lines 598 to 603 in 9766142

	cleanupFn = func() {
	traceCleanupFn()
	if localErr := app.Close(); localErr != nil {
	svrCtx.Logger.Error(localErr.Error())
	}
	}

The function startApp returns the appCleanupFn that contains the call to the stop method and the app that gets passed into startInProcess.

[julienrbrt]

@Mergifyio backport release/v0.50.x

[mergify]

backport release/v0.50.x

✅ Backports have been created

• #17634 fix: remove duplicated app.Close call (backport #17619) has been created for branch release/v0.50.x

[julienrbrt]

Let's (reviewers) watch out to prefix properly the PR.
The end goal is to generate the changelog, but we couldn't do it last time because our commit history was usually bad prefixed.