Turns out Azure Pipelines is doing a few modifications to the base
container. One of the important modification is that they add a new
user to the container that has a passwordless sudo permissions. This
user is used later on to run all the pipeline steps.
This patch makes sure our shared registry inside the docker containers
is accessible to all the users.
Fixes#5635
Instead of symlinking pwuser's registry to root's registry, we now
use the `PLAYWRIGHT_BROWSERS_PATH` variable to define a single
browser registry across the docker image, accessible for all
users.
Fixes#4485
