Plugin::getLogger() interface no longer depends on PluginLogger (#3160)

The Plugin contract now typehints the relied on AttachableLogger contract rather than the concrete PluginLogger implementation.

src/plugin/Plugin.php

@@ -81,9 +81,9 @@ interface Plugin{
 	public function getName() : string;
 
 	/**
-	 * @return PluginLogger
+	 * @return \AttachableLogger
 	 */
-	public function getLogger() : PluginLogger;
+	public function getLogger() : \AttachableLogger;
 
 	/**
 	 * @return PluginLoader

src/plugin/PluginBase.php

@@ -163,9 +163,9 @@ abstract class PluginBase implements Plugin, CommandExecutor{
 	}
 
 	/**
-	 * @return PluginLogger
+	 * @return \AttachableLogger
 	 */
-	public function getLogger() : PluginLogger{
+	public function getLogger() : \AttachableLogger{
 		return $this->logger;
 	}