Update npx commands execution

[elvism-lullabot]

On

ddev-playwright/web-build/disabled.Dockerfile.playwright

Lines 39 to 43 in fd3b8d5

	&& ([ -f yarn.lock ] && export JS_PKG_MANAGER=yarn || export JS_PKG_MANAGER=npx \
	&& sudo -u $username $JS_PKG_MANAGER \
	&& sudo -u $username $JS_PKG_MANAGER playwright install-deps \
	&& sudo -u $username $JS_PKG_MANAGER playwright install \
	) \

we are conditionally executing npx commands depending on the JS_PKG_MANAGER user has which leads to errors if it project is not using yarn