Fix nightlies & untrack json files from git lfs (#414)

tests/data/lerobot/xarm_push_medium_image/meta_data/info.json

@@ -1,3 +1,5 @@
-version https://git-lfs.github.com/spec/v1
-oid sha256:24722873fa5260e960f2c64b1decb02e7bcf31ba44849347e34ea2a268c458e8
-size 65
+{
+    "codebase_version": "v1.6",
+    "fps": 15,
+    "video": 0
+}

tests/data/lerobot/xarm_push_medium_image/train/dataset_info.json

@@ -1,3 +1,51 @@
-version https://git-lfs.github.com/spec/v1
-oid sha256:ba5e9fec857b85adfa021d06c8679f6f7e030c2bfc5d3be3f6590fb250a17d7c
-size 907
+{
+  "citation": "",
+  "description": "",
+  "features": {
+    "observation.image": {
+      "_type": "Image"
+    },
+    "observation.state": {
+      "feature": {
+        "dtype": "float32",
+        "_type": "Value"
+      },
+      "length": 4,
+      "_type": "Sequence"
+    },
+    "action": {
+      "feature": {
+        "dtype": "float32",
+        "_type": "Value"
+      },
+      "length": 3,
+      "_type": "Sequence"
+    },
+    "episode_index": {
+      "dtype": "int64",
+      "_type": "Value"
+    },
+    "frame_index": {
+      "dtype": "int64",
+      "_type": "Value"
+    },
+    "timestamp": {
+      "dtype": "float32",
+      "_type": "Value"
+    },
+    "next.reward": {
+      "dtype": "float32",
+      "_type": "Value"
+    },
+    "next.done": {
+      "dtype": "bool",
+      "_type": "Value"
+    },
+    "index": {
+      "dtype": "int64",
+      "_type": "Value"
+    }
+  },
+  "homepage": "",
+  "license": ""
+}

tests/data/lerobot/xarm_push_medium_image/train/state.json

@@ -1,3 +1,13 @@
-version https://git-lfs.github.com/spec/v1
-oid sha256:939e376b61bed55ef489fdb209444bc22e7e220a3390faa5415b2b39a2612cb5
-size 247
+{
+  "_data_files": [
+    {
+      "filename": "data-00000-of-00001.arrow"
+    }
+  ],
+  "_fingerprint": "e70528672ed7674c",
+  "_format_columns": null,
+  "_format_kwargs": {},
+  "_format_type": null,
+  "_output_all_columns": false,
+  "_split": null
+}