fix: options parser should add trailing slash to 'media' if not prese…

…nt. (google#6263) (google#6264)

* fix: add trailing slash to media option

* fix: add deprecation warning to path option

core/options.js

@@ -15,6 +15,7 @@
  */
 goog.module('Blockly.Options');
 
+const deprecation = goog.require('Blockly.utils.deprecation');
 const idGenerator = goog.require('Blockly.utils.idGenerator');
 const registry = goog.require('Blockly.registry');
 const toolbox = goog.require('Blockly.utils.toolbox');
@@ -105,9 +106,11 @@ class Options {
     }
     let pathToMedia = 'https://blockly-demo.appspot.com/static/media/';
     if (options['media']) {
-      pathToMedia = options['media'];
+      pathToMedia = options['media'].endsWith('/') ? options['media'] :
+                                                     options['media'] + '/';
     } else if (options['path']) {
       // 'path' is a deprecated option which has been replaced by 'media'.
+      deprecation.warn('path', 'Nov 2014', 'Jul 2023', 'media');
       pathToMedia = options['path'] + 'media/';
     }
     let oneBasedIndex;