Playwright docker improvements (#33213)

* Clean up playwright-common Dockerfile

* Speed up element-web docker build

* Wire up element-desktop playwright tests via nx

* Better debug logs for Element Desktop playwright in CI

* Iterate

* Iterate

* Fix element-desktop screenshot docker

* @electron/fuses

* Partial revert

packages/playwright-common/Dockerfile

@@ -6,10 +6,17 @@ ARG PLAYWRIGHT_VERSION
 WORKDIR /work
 
 # fonts-dejavu is needed for the same RTL rendering as on CI
-RUN apt-get update && apt-get -y install docker.io fonts-dejavu
+RUN apt-get update && \
+    apt-get -y install docker.io fonts-dejavu && \
+    apt-get purge -y --auto-remove && \
+    rm -rf /var/lib/apt/lists/*
+
 # Install the matching playwright runtime, the docker image only includes browsers
 RUN npm i -g playwright@${PLAYWRIGHT_VERSION}
 
+# switch to pwuser
+USER 1001:1001
+
 COPY docker-entrypoint.sh /docker-entrypoint.sh
 
 # We use `docker-init` as PID 1, which means that the container shuts down correctly on SIGTERM.