Fix version check

Author: d-j-hatton

src/murfey/bootstrap/__main__.py

@@ -73,7 +73,7 @@ def _download_to_file(url: str, outfile: str):
     # Check that Python version is supported
     print(f"Python version: {sys.version_info.major}.{sys.version_info.minor}")
     # if sys.hexversion < 0x3080000:
-    if sys.version_info >= (3, 9):  # Use version_info tuple instead
+    if sys.version_info < (3, 9):  # Use version_info tuple instead
         exit(
             "Your python version is too old to support Murfey. "
             "You need at least Python 3.9"