Fix mistake in create_entry_points.py (emscripten-core#26623)

`.pa1` -> `.ps1`

Author: podsvirov

tools/maint/create_entry_points.py

@@ -121,7 +121,7 @@ def generate_entry_points(cmd, path):
           shutil.copyfile(windows_exe, launcher + '.exe')
         else:
           write_file(launcher + '.bat', bat_data)
-          write_file(launcher + '.pa1', ps1_data)
+          write_file(launcher + '.ps1', ps1_data)
 
   generate_entry_points(entry_points, os.path.join(__scriptdir__, 'run_python'))
   generate_entry_points(compiler_entry_points, os.path.join(__scriptdir__, 'run_python_compiler'))