chore: removing NLTKDocumentSplitter (#8724)

* removing NLTKDocumentSplitter

* adding release notes

* removing pydocs reference

Author: davidsbatista

Diff for: docs/pydoc/config/preprocessors_api.yml

@@ -1,7 +1,7 @@
 loaders:
   - type: haystack_pydoc_tools.loaders.CustomPythonLoader
     search_path: [../../../haystack/components/preprocessors]
-    modules: ["document_cleaner", "document_splitter", "nltk_document_splitter", "recursive_splitter", "text_cleaner"]
+    modules: ["document_cleaner", "document_splitter", "recursive_splitter", "text_cleaner"]
     ignore_when_discovered: ["__init__"]
 processors:
   - type: filter

Diff for: haystack/components/preprocessors/__init__.py

@@ -4,8 +4,7 @@
 
 from .document_cleaner import DocumentCleaner
 from .document_splitter import DocumentSplitter
-from .nltk_document_splitter import NLTKDocumentSplitter
 from .recursive_splitter import RecursiveDocumentSplitter
 from .text_cleaner import TextCleaner
 
-__all__ = ["DocumentSplitter", "DocumentCleaner", "RecursiveDocumentSplitter", "TextCleaner", "NLTKDocumentSplitter"]
+__all__ = ["DocumentSplitter", "DocumentCleaner", "RecursiveDocumentSplitter", "TextCleaner"]

Diff for: haystack/components/preprocessors/nltk_document_splitter.py

@@ -0,0 +1,4 @@
+---
+upgrade:
+  - |
+    Removed the deprecated `NLTKDocumentSplitter`, it's functionalities are now supported by the `DocumentSplitter`.