Computer loadstatistics is broken since 2.289.1.2 - api shows data, but graphs do not render.

Beginning with upgrade to 2.289.1.2 we noticed that loadStatistics for labels and agents is now borked.

E.g. /label/VALIDLABEL/load-statistics shows a broken icon for the statistics, while
/label/VALIDLABEL/loadStatistics/graph?type=min&width=1295&height=500

Shows an OOPS demon jenkins with an error.

However `label/VALIDLABEL/api/python?pretty=true&depth=3` does provide the expected values.

See attached screenshots.

We also recently removed several plugins as suggested by the Jenkins Health Advisor (tables-to-div issues as well as obsolete plugins).

We make use of these statistics to help understand loads on our agents - usually by LABEL.
Load-statistics are similarly broken for agents, too, e.g.

`/computer/VALIDAGENTNAME/load-statistics` is similarly broken.

Since we had recently upgraded the monitoring plugin, we downgraded that and restarted but no help there.