refactor: remove cometbft/libs/cli import

[julienrbrt]

Description

ref: #14726 (comment)
This showed up in my notifications, and it was quick to do.

Keeps PrepareBaseCmd for avoiding code duplication and ensure env variable can be read by cmt.

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[tac0turtle]

LGTM, thanks for the quick push

[samricotta]

Looks good ! :)