Fix: Quote Python path to handle spaces in postinstall scripts

Wraps Python executable path in quotes when it contains spaces before executing package postinstall scripts. This fixes installation failures on Windows when Python is installed in directories like 'Program Files'.

Fixes #5361

Author: alex-lisi

platformio/package/manager/base.py

@@ -335,7 +335,11 @@ def call_pkg_script(self, pkg, event):
         os.environ["PIO_PYTHON_EXE"] = get_pythonexe_path()
         with fs.cd(pkg.path):
             if os.path.isfile(cmd[0]) and cmd[0].endswith(".py"):
-                cmd = [os.environ["PIO_PYTHON_EXE"]] + cmd
+                python_exe = os.environ["PIO_PYTHON_EXE"]
+                # Quote the path if it contains spaces (Windows compatibility)
+                if " " in python_exe:
+                    python_exe = f'"{python_exe}"'
+                    cmd = [python_exe] + cmd
             subprocess.run(
                 " ".join(cmd) if shell else cmd,
                 cwd=pkg.path,