This ruleset reference notation has been deprecated with PMD 6.46.0. Also the internal
release rulesets notation (e.g. "6460" -> "rulesets/releases/6460.xml") are not supported anymore.

Related previous issues:

• [core] Deprecate <lang>-<ruleset> hyphen notation for ruleset references #2352
• [core] Deprecate some syntax for ruleset references #3958