BREAKING CHANGE: remove browser build, move to @mongoosejs/browser instead

Fix #15296

Author: vkarpov15

browser.js

@@ -34,5 +34,4 @@ And Next.js forces ESM mode.
 ## Next.js Edge Runtime
 
 Mongoose does **not** currently support [Next.js Edge Runtime](https://nextjs.org/docs/app/building-your-application/rendering/edge-and-nodejs-runtimes#edge-runtime).
-While you can import Mongoose in Edge Runtime, you'll get [Mongoose's browser library](browser.html).
 There is no way for Mongoose to connect to MongoDB in Edge Runtime, because [Edge Runtime currently doesn't support Node.js `net` API](https://edge-runtime.vercel.app/features/available-apis#unsupported-apis), which is what the MongoDB Node Driver uses to connect to MongoDB.

docs/nextjs.md

@@ -92,19 +92,20 @@ function Document(obj, fields, skipId, options) {
   }
   options = Object.assign({}, options);
 
+  this.$__ = new InternalCache();
+
   // Support `browserDocument.js` syntax
   if (this.$__schema == null) {
     const _schema = utils.isObject(fields) && !fields.instanceOfSchema ?
       new Schema(fields) :
       fields;
+
     this.$__setSchema(_schema);
     fields = skipId;
     skipId = options;
     options = arguments[4] || {};
   }
 
-  this.$__ = new InternalCache();
-
   // Avoid setting `isNew` to `true`, because it is `true` by default
   if (options.isNew != null && options.isNew !== true) {
     this.$isNew = options.isNew;
@@ -848,10 +849,10 @@ Document.prototype.updateOne = function updateOne(doc, options, callback) {
   const query = this.constructor.updateOne({ _id: this._doc._id }, doc, options);
   const self = this;
   query.pre(function queryPreUpdateOne() {
-    return self.constructor._middleware.execPre('updateOne', self, [self]);
+    return self._execDocumentPreHooks('updateOne', [self]);
   });
   query.post(function queryPostUpdateOne() {
-    return self.constructor._middleware.execPost('updateOne', self, [self], {});
+    return self._execDocumentPostHooks('updateOne');
   });
 
   if (this.$session() != null) {
@@ -2903,15 +2904,15 @@ function _pushNestedArrayPaths(val, paths, path) {
  */
 
 Document.prototype._execDocumentPreHooks = async function _execDocumentPreHooks(opName, ...args) {
-  return this.constructor._middleware.execPre(opName, this, [...args]);
+  return this.$__middleware.execPre(opName, this, [...args]);
 };
 
 /*!
  * ignore
  */
 
 Document.prototype._execDocumentPostHooks = async function _execDocumentPostHooks(opName, error) {
-  return this.constructor._middleware.execPost(opName, this, [this], { error });
+  return this.$__middleware.execPost(opName, this, [this], { error });
 };
 
 /*!
@@ -3653,6 +3654,7 @@ Document.prototype.$__setSchema = function(schema) {
     this.schema = schema;
   }
   this.$__schema = schema;
+  this.$__middleware = schema._getDocumentMiddleware();
   this[documentSchemaSymbol] = schema;
 };