Allow screenshot update docker to run multiple test files (#12291)

The entrypoint script only passed the first argument so if you specified
multiple test files it would only run the first.

This will need the docker image to be rebuilt on each machine you run it
on to take effect.

playwright/docker-entrypoint.sh

@@ -5,4 +5,4 @@ set -e
 yarn link
 yarn --cwd ../element-web install
 yarn --cwd ../element-web link matrix-react-sdk
-npx playwright test --update-snapshots --reporter line --project='Legacy Crypto' $1
+npx playwright test --update-snapshots --reporter line --project='Legacy Crypto' $@