Fix plugin loading in Windows (#3043)

We use `File.toURI` for more stable URI, since the previous
method stopped working on Java 21 on Windows.

Author: DerEwige

eclair-node/src/main/scala/fr/acinq/eclair/Plugin.scala

@@ -58,7 +58,7 @@ object Plugin extends Logging {
   }
 
   def openJar(jar: File): Option[JarURLConnection] =
-    Try(URI.create(s"jar:file:${jar.getCanonicalPath}!/").toURL.openConnection().asInstanceOf[JarURLConnection]) match {
+    Try(URI.create(s"jar:${jar.toURI}!/").toURL.openConnection().asInstanceOf[JarURLConnection]) match {
       case Success(url) => Some(url)
       case Failure(t) => logger.error(s"unable to load plugin file:${jar.getAbsolutePath} ", t); None
     }