feat: Unfreeze Document in Haystack 2.0 (#5974)

* Unfreeze document

* Remove immutability test

haystack/preview/dataclasses/document.py

@@ -1,15 +1,13 @@
-from typing import List, Any, Dict, Optional, Type
-
-import json
 import hashlib
+import json
 import logging
+from dataclasses import asdict, dataclass, field, fields
 from pathlib import Path
-from dataclasses import dataclass, field, fields, asdict
+from typing import Any, Dict, List, Optional, Type
 
 import numpy
 import pandas
 
-
 logger = logging.getLogger(__name__)
 
 
@@ -50,7 +48,7 @@ def document_decoder(self, dictionary):
         return dictionary
 
 
-@dataclass(frozen=True)
+@dataclass
 class Document:
     """
     Base data class containing some data to be queried.

test/preview/dataclasses/test_document.py

@@ -1,21 +1,14 @@
-from pathlib import Path
 import dataclasses
-import textwrap
 import json
+import textwrap
+from pathlib import Path
 
-import pytest
-import pandas as pd
 import numpy as np
+import pandas as pd
+import pytest
 
 from haystack.preview import Document
-from haystack.preview.dataclasses.document import DocumentEncoder, DocumentDecoder
-
-
-@pytest.mark.unit
-def test_document_is_immutable():
-    doc = Document(text="test text")
-    with pytest.raises(dataclasses.FrozenInstanceError):
-        doc.text = "won't work"
+from haystack.preview.dataclasses.document import DocumentDecoder, DocumentEncoder
 
 
 @pytest.mark.unit