Revert "mount the SSH_AUTH_SOCK socket for ssh-agent"

[thavaahariharangit]

Reverts #11683

As @robaiken has raised an issue with this config.

docker: Error response from daemon: error while creating mount source path '/host_mnt/private/tmp/com.apple.launchd.Q3NRTvcke4/Listeners': mkdir /host_mnt/private/tmp/com.apple.launchd.Q3NRTvcke4/Listeners: operation not supported```

@dmitris Need your thoughts on this pls

FYI @abdulapopoola

[dmitris]

I asked in #11683 ("Anything you want to highlight for special attention from reviewers?"):

I wonder if I should add a flag to activate propagation of the ssh credentials (so that you wouldn't have anything changed compared to the status quo without the flag)?

I would suggest we put the ssh credentials propagation under the flag (such as --ssh-agent), so that it could be used by those who need it, but otherwise it would not change anything.