Minor docker cleanup

run-tests/Dockerfile

@@ -8,7 +8,7 @@ ARG CITRA_CHANNEL=nightly
 ARG CITRA_RELEASE=1995
 RUN download_citra ${CITRA_CHANNEL} ${CITRA_RELEASE}
 
-FROM devkitpro/devkitarm as devkitarm
+FROM devkitpro/devkitarm:latest as devkitarm
 
 # For some reason, citra isn't always happy when you try to run it for the first time,
 # so we build a simple dummy program to force it to create its directory structure

run-tests/docker/entrypoint.sh

@@ -1,6 +1,10 @@
 #!/bin/bash
 
-set -x
+# Uncomment for debugging the action itself. Maybe consider a job summary or
+# grouping the output, to keep this stuff visible but make it simpler to use:
+# https://docs.github.com/en/actions/using-workflows/workflow-commands-for-github-actions
+
+# set -x
 
 function cleanup_jobs() {
     # shellcheck disable=SC2317 # Unreachable because it's only used in trap