DEV: Revert uppy upgrade

This rolls uppy back to the previous bundle that was used,
which will break multipart functionality (which is not yet
enabled anywhere).

No other upload functionality should be affected by this change,
it will be as if d295a16dab had
not been merged.

app/assets/javascripts/discourse-shims.js

@@ -32,7 +32,7 @@ define("@popperjs/core", ["exports"], function (__exports__) {
 
 define("@uppy/core", ["exports"], function (__exports__) {
   __exports__.default = window.Uppy.Core;
-  __exports__.BasePlugin = window.Uppy.BasePlugin;
+  __exports__.Plugin = window.Uppy.Plugin;
 });
 
 define("@uppy/aws-s3", ["exports"], function (__exports__) {

app/assets/javascripts/discourse/app/lib/uppy-checksum-plugin.js

@@ -1,8 +1,8 @@
-import { BasePlugin } from "@uppy/core";
+import { Plugin } from "@uppy/core";
 import { warn } from "@ember/debug";
 import { Promise } from "rsvp";
 
-export default class UppyChecksum extends BasePlugin {
+export default class UppyChecksum extends Plugin {
   constructor(uppy, opts) {
     super(uppy, opts);
     this.id = opts.id || "uppy-checksum";

app/assets/javascripts/discourse/app/lib/uppy-media-optimization-plugin.js

@@ -1,8 +1,8 @@
-import { BasePlugin } from "@uppy/core";
+import { Plugin } from "@uppy/core";
 import { warn } from "@ember/debug";
 import { Promise } from "rsvp";
 
-export default class UppyMediaOptimization extends BasePlugin {
+export default class UppyMediaOptimization extends Plugin {
   constructor(uppy, opts) {
     super(uppy, opts);
     this.id = opts.id || "uppy-media-optimization";