Rename setup function to _setup_pipenv_minimal

Author: Jason2866

platform.py

@@ -848,7 +848,7 @@ def configure_default_packages(self, variables: Dict, targets: List[str]) -> Any
             core_dir = config.get("platformio", "core_dir")
 
             # Setup penv using minimal function (no SCons dependencies, esptool from tl-install)
-            penv_python, esptool_path = setup_penv_minimal(self, core_dir, install_esptool=True)
+            penv_python, esptool_path = _setup_pipenv_minimal(self, core_dir, install_esptool=True)
 
             # Store both for later use
             self._penv_python = penv_python