only write if file changed (#4822)

* only write if file changed

* preface it on it existing

reflex/compiler/utils.py

@@ -523,6 +523,8 @@ def write_page(path: str | Path, code: str):
     """
     path = Path(path)
     path_ops.mkdir(path.parent)
+    if path.exists() and path.read_text(encoding="utf-8") == code:
+        return
     path.write_text(code, encoding="utf-8")