Update sbt-pgp to 2.3.1 (#1784)

Author: scala-steward

project/plugins.sbt

@@ -2,7 +2,7 @@ val scalaJSVersion = Option(System.getenv("SCALAJS_VERSION")).getOrElse("1.16.0"
 
 addSbtPlugin("com.eed3si9n" % "sbt-assembly" % "0.14.10")
 
-addSbtPlugin("com.github.sbt" % "sbt-pgp" % "2.2.1")
+addSbtPlugin("com.github.sbt" % "sbt-pgp" % "2.3.1")
 
 addSbtPlugin("com.github.sbt" % "sbt-native-packager" % "1.10.4")