rocket: Don't try to build Boost binding code for Python 3

libRocket doesn't support Python 3 anyway, and it has an error compiling with Python 3.11

[skip ci]

doc/ReleaseNotes

@@ -42,6 +42,7 @@ Miscellaneous
 * Add additional helpful debug/spam prints to display code
 
 Build
+* Support building with Python 3.11
 * Support building with OpenSSL 1.1.1 on Windows
 * Support building with OpenEXR 3.0 or 3.1 on Windows
 * Fix errors when compiling Panda headers with MinGW

panda/src/rocket/rocketRegion_ext.cxx

@@ -16,7 +16,7 @@
 
 #ifdef HAVE_PYTHON
 
-#ifndef CPPPARSER
+#if !defined(CPPPARSER) && PY_MAJOR_VERSION < 3
 #define HAVE_LONG_LONG 1
 #include <Rocket/Core/Context.h>
 #include <Rocket/Core/Python/Utilities.h>
@@ -30,6 +30,7 @@
  */
 PyObject* Extension<RocketRegion>::
 get_context() const {
+#if PY_MAJOR_VERSION < 3
   try {
     Rocket::Core::Context* context = _this->get_context();
     python::object py_context = Rocket::Core::Python::Utilities::MakeObject(context);
@@ -44,6 +45,7 @@ get_context() const {
     (void)e;
     // Return NULL, which will trigger the exception in Python
   }
+#endif
   return nullptr;
 }