Currently the history graphs for test results are generated on the server side. This requires a non-headless jdk to be installed in order to work correctly (when using openjdk). This is an issue since installing the non-headless jdk contains a lot of unnecessary dependencies and X-11 components which are definitely not required on a server.
My proposal is to migrate the graphs to the [ECharts API|https://plugins.jenkins.io/echarts-api/] as already used by the warnings-ng plugin.
This would allow for a simpler server side code, allow access to the history data via an api and get rid of the X-11 dependencies that a non-headless jdk comes with.
I'm planning to do the implementation but I'm happy to hear your thoughts on this topic and if a PR for this would make sense.