Update dependency io.github.manamiproject:modb-test to v1.6.20

Author: renovate[bot]

gradle/libs.versions.toml

@@ -11,7 +11,7 @@ modb-kitsu = "5.1.4"
 modb-livechart = "3.1.3"
 modb-myanimelist = "6.1.3"
 modb-notify = "5.1.3"
-modb-test = "1.6.19"
+modb-test = "1.6.20"
 commons-text = "1.12.0"
 commons-lang3 = "3.16.0"
 logback-classic = "1.5.7"