[api-major] Remove (most of) the remaining deprecated code

There's three notable exceptions here:
 - The `saveDocument` one is converted into a permanent `warn`, since it still works when the `annotationStorage` is empty although it's (obviously) less efficient than `getData`.
 - The `fallbackWorkerSrc` functionality (for browsers), since just removing it would risk too much third-party breakage.
 - The SVG back-end, since a final decision is yet to be made. (It might be completely removed, or left as-is in an essentially "frozen" state.)

web/ui_utils.js

@@ -699,15 +699,6 @@ class ProgressBar {
   #visible = true;
 
   constructor(id) {
-    if (
-      (typeof PDFJSDev === "undefined" || PDFJSDev.test("GENERIC")) &&
-      arguments.length > 1
-    ) {
-      throw new Error(
-        "ProgressBar no longer accepts any additional options, " +
-          "please use CSS rules to modify its appearance instead."
-      );
-    }
     const bar = document.getElementById(id);
     this.#classList = bar.classList;
   }