Removes deprecated --parallel switch on compose

Description

As of `docker-compose` 1.21.0, `pull` uses `--parallel` by default([1]).

[1]: https://github.com/docker/compose/pull/5787

Status

Assignee

Unassigned

Reporter

Open Source Pull Request Bot

Contributor Name

Matt Bajor

Repo

edx/devstack

Customer

None

Epic Link

None

OSCM Assignee

None

Platform Map Area (Levels 1 & 2)

Site Delivery & Infrastructure

Platform Map Area (Levels 3 & 4)

None

Priority

Unset
Configure