[smart-switch][dpu] Do not run dhclient on the eth0 interface.

[oleksandrivantsiv]

Why I did it

The Smart Switch DPU uses midplane-eth0 interface instead of eth0 for the control plane access. The tails are described in IP address asignment HLD.
When the dhclient is running on top of eth0 interface that is down on the Smart Switch DPU it generates errors in the logs:

ERR dhclient[2083]: send_packet: Network is down
2024 Nov 19 15:27:42.157924 sonic ERR dhclient[2083]: send_packet: Network is down
2024 Nov 19 15:27:42.158000 sonic ERR dhclient[2083]: dhclient.c:2600: Failed to send 300 byte long packet over eth0 interface.

Work item tracking

• Microsoft ADO (number only):

How I did it

Do not run dhclient on the eth0 interface.

How to verify it

Run the image on the Smart Switch DPU. Generated /etc/network/interfaces should not contain dhcp configuration for the eth0 interface.

Which release branch to backport (provide reason below if selected)

• 201811
• 201911
• 202006
• 202012
• 202106
• 202111
• 202205
• 202211
• 202305

Tested branch (Please provide the tested image version)

Description for the changelog

Link to config_db schema for YANG module changes

A picture of a cute animal (not mandatory but encouraged)

[oleksandrivantsiv]

/azpw ms_conflict

[oleksandrivantsiv]

/azpw run

[mssonicbld]

/AzurePipelines run

[azure-pipelines]

Azure Pipelines successfully started running 1 pipeline(s).

[prsunny]

@kperumalbfn , please merge

[kperumalbfn]

LGTM

[mssonicbld]

Cherry-pick PR to 202411: #21125