Update properties to use semver format

Author: helin24

third_party/gradle.properties

@@ -7,7 +7,7 @@ pluginName = Dart
 pluginId = Dart
 
 # SemVer format -> https://semver.org
-pluginVersion = 500.0
+pluginVersion = 500.0.0
 
 # TODO(https://github.com/flutter/dart-intellij-third-party/issues/23) Add a changelog
 # Not currently used in the build.gradle.kts file: