Typo on flatten-dict dependency (#10953)

Author: weiji14

pyproject.toml

@@ -47,7 +47,7 @@ dependencies = [
     "dvc-render>=1.0.1,<2",
     "dvc-studio-client>=0.21,<1",
     "dvc-task>=0.3.0,<1",
-    "flatten_dict<1,>=0.4.1",
+    "flatten-dict<1,>=0.4.1",
     "flufl.lock>=8.1.0,<10",
     "fsspec>=2024.2.0",
     "funcy>=1.14",