[sonic-utilities] submodule update (#8284)

This PR updates the following commits

a9606fb [show] fix show muxcable metrics <port> for sorted output (#1731)
7355016 [minigraph][port_config] Use imported config.main and add conditional patch (#1728)
cc1d6e4 [configlet] Python3 compatible syntax for extracting a key from the dict (#1721)

Signed-off-by: vaibhav-dahiya <[email protected]>