chore: bump nltk from 3.9.3 to 3.9.4 in /libs/text-splitters (#36237)

Bumps [nltk](https://github.com/nltk/nltk) from 3.9.3 to 3.9.4.
<details>
<summary>Changelog</summary>
<p><em>Sourced from <a
href="https://github.com/nltk/nltk/blob/develop/ChangeLog">nltk's
changelog</a>.</em></p>
<blockquote>
<p>Version 3.9.4 2026-03-24</p>
<ul>
<li>Support Python 3.14</li>
<li>Fix bug in Levenshtein distance when substitution_cost &gt; 2</li>
<li>Fix bug in Treebank detokeniser re quote ordering</li>
<li>Fix bug in Jaro similarity for empty strings</li>
<li>Several security enhancements</li>
<li>Fix GHSA-rf74-v2fm-23pw: unbounded recursion in
JSONTaggedDecoder</li>
<li>Implement TextTiling vocabulary introduction method (Hearst
1997)</li>
<li>Fix ALINE feature matrix errors and add comprehensive tests</li>
<li>Support multiple VerbNet versions, fix longid/shortid regex for
VerbNet ids</li>
<li>Let downloader fallback to md5 when sha256 is unavailable</li>
<li>Several other minor bugfixes and code cleanups</li>
</ul>
<p>Thanks to the following contributors to 3.9.4:
Min-Yen Kan, Eric Kafe, Emily Voss, bowiechen, Hrudhai01,
jancallewaert, Mr-Neutr0n, pollak.peter89, ylwango613,</p>
<p>Version 3.9.3 2026-02-21</p>
<ul>
<li>Fix CVE-2025-14009: secure ZIP extraction in nltk.downloader (<a
href="https://redirect.github.com/nltk/nltk/issues/3468">#3468</a>)</li>
<li>Block path traversal/arbitrary reads in nltk.data for protocol-less
refs (<a
href="https://redirect.github.com/nltk/nltk/issues/3467">#3467</a>)</li>
<li>Block path traversal/abs paths in corpus readers and FS pointers (<a
href="https://redirect.github.com/nltk/nltk/issues/3479">#3479</a>, <a
href="https://redirect.github.com/nltk/nltk/issues/3480">#3480</a>)</li>
<li>Validate external StanfordSegmenter JARs using SHA256 (<a
href="https://redirect.github.com/nltk/nltk/issues/3477">#3477</a>)</li>
<li>Add optional sandbox enforcement for filestring() (<a
href="https://redirect.github.com/nltk/nltk/issues/3485">#3485</a>)</li>
<li>Maintenance: downloader/zipped models, CI/tooling updates</li>
</ul>
<p>Thanks to the following contributors to 3.9.3:
Chris Clauss, Eric Kafe, HyperPS, purificant, Shivansh-Game, Christopher
Smith</p>
<p>Version 3.9.2 2025-10-01</p>
<ul>
<li>Update download checksums to use SHA256 in built index</li>
<li>Fix percentage escape in new-style string formatting</li>
<li>replace shortened URLs using goo.gl</li>
<li>Make Wordnet interoperable with various taggers and tagged
corpora</li>
<li>Fix saving PerceptronTagger</li>
<li>Document how to reproduce old Wordnet studies</li>
<li>properly initialize Portuguese corpus reader</li>
<li>support for mixed rules conversion into Chomsky Normal Form</li>
<li>only import tkinter if a GUI is needed</li>
<li>issue <a
href="https://redirect.github.com/nltk/nltk/issues/2112">#2112</a> with
Corenlp</li>
<li>new environment variable
NLTK_DOWNLOADER_FORCE_INTERACTIVE_SHELL</li>
<li>Lesk defaults to most frequent sense in case of ties</li>
</ul>
<p>Thanks to the following contributors to 3.9.2:
Jose Cols, Peter de Blanc, GeneralPoxter, Eric Kafe, William LaCroix,
Jason Liu,
Samer Masterson, Mike014, purificant, Andrew Ernest Ritz, samertm, Ikram
Ul Haq,
Christopher Smith, Ryan Mannion</p>
<p>Version 3.9.1 2024-08-19</p>
<!-- raw HTML omitted -->
</blockquote>
<p>... (truncated)</p>
</details>
<details>
<summary>Commits</summary>
<ul>
<li><a
href="https://github.com/nltk/nltk/commit/ad9c96ba00a16923ffe917eacf63f1707bfa2d08"><code>ad9c96b</code></a>
Update copyright year</li>
<li><a
href="https://github.com/nltk/nltk/commit/7edcddfda566627b897397397cc4d10ae91cb86d"><code>7edcddf</code></a>
Updates for 3.9.4 release</li>
<li><a
href="https://github.com/nltk/nltk/commit/67a2736f89b286b028db08bd247134f17a11fc6b"><code>67a2736</code></a>
Merge pull request <a
href="https://redirect.github.com/nltk/nltk/issues/3180">#3180</a> from
yzhaoinuw/bug-on-edit_distance_align</li>
<li><a
href="https://github.com/nltk/nltk/commit/2b17ac5358a1c8d4b97455766efde0b786e6cdb2"><code>2b17ac5</code></a>
Fix edit_distance_align backtrace for high substitution costs</li>
<li><a
href="https://github.com/nltk/nltk/commit/4b72976a6ff3d180ed4012f11843e611a8f89516"><code>4b72976</code></a>
Merge pull request <a
href="https://redirect.github.com/nltk/nltk/issues/3018">#3018</a> from
JuanIMartinezB/bug/shortid-longid</li>
<li><a
href="https://github.com/nltk/nltk/commit/8a5619f53a281149e5342b1a00fe05fe2fc6517f"><code>8a5619f</code></a>
Merge pull request <a
href="https://redirect.github.com/nltk/nltk/issues/3222">#3222</a> from
Syzygy2048/feature/texttiling-vocabulary-introd...</li>
<li><a
href="https://github.com/nltk/nltk/commit/c6574d755e02b6163d9cd1d0b407076940e08864"><code>c6574d7</code></a>
Merge pull request <a
href="https://redirect.github.com/nltk/nltk/issues/3289">#3289</a> from
ihitamandal/codeflash/optimize-windowdiff-2024-...</li>
<li><a
href="https://github.com/nltk/nltk/commit/98ff5d9eaa1a81511873b9aef857944519c28dc4"><code>98ff5d9</code></a>
Merge pull request <a
href="https://redirect.github.com/nltk/nltk/issues/3435">#3435</a> from
Hrudhai01/fix-3260-detokenize-quotes</li>
<li><a
href="https://github.com/nltk/nltk/commit/aec4fce1b84ad725b8975f7365b23a4f626572a9"><code>aec4fce</code></a>
Merge pull request <a
href="https://redirect.github.com/nltk/nltk/issues/3522">#3522</a> from
ekaf/pathsec</li>
<li><a
href="https://github.com/nltk/nltk/commit/eec4ee3591cb9cb8b8c2989f08012608c841d532"><code>eec4ee3</code></a>
Merge pull request <a
href="https://redirect.github.com/nltk/nltk/issues/3526">#3526</a> from
nltk/update-contributing</li>
<li>Additional commits viewable in <a
href="https://github.com/nltk/nltk/compare/3.9.3...3.9.4">compare
view</a></li>
</ul>
</details>
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