<commit_before><commit_msg>DOC: Add release note mentioning change to subarray->object cast<commit_after>Subarray to object cast now copies
----------------------------------
Casting a dtype that includes a subarray to an object will now ensure
a copy of the subarray.  Previously an unsafe view was returned::

    arr = np.ones(3, dtype=[("f", "i", 3)])
    subarray_fields = arr.astype(object)[0]
    subarray = subarray_fields[0]  # "f" field

    np.may_share_memory(subarray, arr)

Is now always false.  While previously it was true for the specific cast.
{'fraction_non_alphanumeric': 0.14260249554367202, 'fraction_numerical': 0.0071301247771836, 'mean_word_length': 3.257575757575758, 'pattern_counts': {'":': 0, '<': 3, '<?xml version=': 0, '>': 4, 'https://': 0, 'lorem ipsum': 0, 'www.': 0, 'xml': 0}, 'pii_count': 0, 'substrings_counts': 0, 'word_list_counts': {'cursed_substrings.json': 0, 'profanity_word_list.json': 0, 'sexual_word_list.json': 0, 'zh_pornsignals.json': 0}}
{'dir': 'git-commits-cleaned', 'id': '2136497', 'n_tokens_mistral': 163, 'n_tokens_neox': 156, 'n_words': 64}