Update jfreechart to 1.5.6

[rolandas-karosas]

Update jfreechart from 1.5.4 to 1.5.6
As 1.5.4 reports 1 vulnerability https://central.sonatype.com/artifact/org.jfree/jfreechart/versions

[teodord]

Can you please provide a link to the vulnerability?

[rolandas-karosas]

https://nvd.nist.gov/vuln/detail/CVE-2023-52070
GHSA-872f-jfmv-qjp2

v1.5.5 made some related changes (https://github.com/jfree/jfreechart/releases/tag/v1.5.5):
CVE-2023-52070 : an ArrayIndexOutOfBoundsException in CompassPlot
No fix is considered necessary, however (jfree/jfreechart#397) has been applied.