Revert "refactor: use aws-sdk-js instead of boto (#24863)"

This reverts commit a3581aa992.

docs/development/source-code-directory-structure.md

@@ -101,5 +101,33 @@ script/ - The set of all scripts Electron runs for a variety of purposes.
 * **tools** - Helper scripts used by GN files.
   * Scripts put here should never be invoked by users directly, unlike those in `script`.
 * **typings** - TypeScript typings for Electron's internal code.
-* **vendor** - Source code for some third party dependencies.
+* **vendor** - Source code for some third party dependencies, including `boto` and `requests`.
 
+## Keeping Git Submodules Up to Date
+
+The Electron repository has a few vendored dependencies, found in the
+[/vendor][vendor] directory. Occasionally you might see a message like this
+when running `git status`:
+
+```sh
+$ git status
+
+	modified:   vendor/depot_tools (new commits)
+	modified:   vendor/boto (new commits)
+```
+
+To update these vendored dependencies, run the following command:
+
+```sh
+git submodule update --init --recursive
+```
+
+If you find yourself running this command often, you can create an alias for it
+in your `~/.gitconfig` file:
+
+```sh
+[alias]
+	su = submodule update --init --recursive
+```
+
+[vendor]: https://github.com/electron/electron/tree/master/vendor