Update plotsquared to v7.5.9 (#3369)

Co-authored-by: renovate[bot] <29139614+renovate[bot]@users.noreply.github.com>

Author: renovate[bot]

gradle/libs.versions.toml

@@ -14,7 +14,7 @@ griefprevention = "18.0.0"
 griefdefender = "2.1.0-SNAPSHOT"
 residence = "6.0.0.1"
 towny = "0.101.2.6"
-plotsquared = "7.5.8"
+plotsquared = "7.5.9"
 
 # Third party
 bstats = "3.1.0"