build_ext: Support C++ for RPYBUILD_CC_LAUNCHER (#244)

setuptools v72.2.0 added realer support for C++, which includes
understanding the C++ compiler usually has a different name.

pypa/setuptools@2c93711

robotpy_build/command/build_ext.py

@@ -107,6 +107,11 @@ def build_extensions(self):
             if cc_launcher:
                 self.compiler.compiler.insert(0, cc_launcher)
                 self.compiler.compiler_so.insert(0, cc_launcher)
+                try:
+                    # setuptools v72.2.0 added C++ support
+                    self.compiler.compiler_so_cxx.insert(0, cc_launcher)
+                except AttributeError:
+                    pass
                 # compiler_cxx is only used for linking, so we don't mess with it
                 # .. distutils is so weird
                 # self.compiler.compiler_cxx.insert(0, cc_launcher)