fix: Set parameter usedforsecurity=False when calling hashlib.md5 in order to fix rag_tool.insert on FIPS clusters (#2577)

# What does this PR do?
Set parameter `usedforsecurity=False` when calling hashlib.md5 in order
to fix rag_tool.insert on FIPS clusters

<!-- If resolving an issue, uncomment and update the line below -->
Closes #2571

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Signed-off-by: Jorge Garcia Oncins <jgarciao@redhat.com>

llama_stack/providers/utils/vector_io/chunk_utils.py

@@ -9,6 +9,11 @@ import uuid
 
 
 def generate_chunk_id(document_id: str, chunk_text: str) -> str:
-    """Generate a unique chunk ID using a hash of document ID and chunk text."""
+    """
+    Generate a unique chunk ID using a hash of the document ID and chunk text.
+
+    Note: MD5 is used only to calculate an identifier, not for security purposes.
+    Adding usedforsecurity=False for compatibility with FIPS environments.
+    """
     hash_input = f"{document_id}:{chunk_text}".encode()
-    return str(uuid.UUID(hashlib.md5(hash_input).hexdigest()))
+    return str(uuid.UUID(hashlib.md5(hash_input, usedforsecurity=False).hexdigest()))