Matched the other encode calls

Author: jm12138

setup.py

@@ -3,7 +3,7 @@
 from pathlib import Path
 
 this_directory = Path(__file__).parent
-long_description = (this_directory / "README.md").read_text(encoding='UTF-8')
+long_description = (this_directory / "README.md").read_text(encoding="utf-8")
 
 setup(
     name="llama_cpp_python",