[Editor] Remove the option enableStamp

web/app_options.js

@@ -172,14 +172,6 @@ const defaultOptions = {
     value: typeof PDFJSDev === "undefined" || !PDFJSDev.test("CHROME"),
     kind: OptionKind.VIEWER + OptionKind.PREFERENCE,
   },
-  enableStampEditor: {
-    // We'll probably want to make some experiments before enabling this
-    // in Firefox release, but it has to be temporary.
-    // TODO: remove it when unnecessary.
-    /** @type {boolean} */
-    value: true,
-    kind: OptionKind.VIEWER + OptionKind.PREFERENCE,
-  },
   externalLinkRel: {
     /** @type {string} */
     value: "noopener noreferrer nofollow",