Revert "Use python3 to update bindings (#6068)" (#6071)

This reverts commit 6edf63e.

Only show in developer changelog

Author: AlexandreSi

GDevelop.js/README.md

@@ -10,7 +10,7 @@ These are the bindings of GDevelop core classes to WebAssembly+JavaScript. This
 
   - [CMake 3.17+](http://www.cmake.org/) (3.5+ should work on Linux/macOS). On macOS, you can install it via Homebrew (recommended for Apple M1 Architectures).
   - [Node.js](https://nodejs.org/). (We recommend using [nvm](https://github.com/nvm-sh/nvm) to be able to switch between Node versions easily).
-  - Python3 (via [pyenv](https://github.com/pyenv/pyenv) for versions management).
+  - Python (via [pyenv](https://github.com/pyenv/pyenv) for versions management).
 
 - Install [Emscripten](https://github.com/kripken/emscripten) version `3.1.21`, as explained below or on the [Emscripten installation instructions](http://kripken.github.io/emscripten-site/docs/getting_started/downloads.html):
 

GDevelop.js/update-bindings.js

@@ -40,7 +40,7 @@ function generateGlueFromBinding(cb) {
     }
 
     exec(
-      'python3 "' + webIdlBinderPath + '" Bindings/Bindings.idl Bindings/glue',
+      'python "' + webIdlBinderPath + '" Bindings/Bindings.idl Bindings/glue',
       function(err, stdout, stderr) {
         if (err) {
           cb({ message: 'Error while running WebIDL binder:', output: err });