chore: bump bleach from 6.2.0 to 6.4.0 in /libs/langchain (#38196)

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[//]: # (dependabot-end)

Bumps [bleach](https://github.com/mozilla/bleach) from 6.2.0 to 6.4.0.
<details>
<summary>Changelog</summary>
<p><em>Sourced from <a
href="https://github.com/mozilla/bleach/blob/main/CHANGES">bleach's
changelog</a>.</em></p>
<blockquote>
<h2>Version 6.4.0 (June 5th, 2026)</h2>
<p><strong>NOTE: 2026-06-05: Bleach is no longer maintained. There will
be no future
releases including for security issues.</strong>
See issue:
<code>&lt;https://github.com/mozilla/bleach/issues/698&gt;</code>__</p>
<p><strong>Backwards incompatible changes</strong></p>
<ul>
<li>Dropped support for pypy 3.10. (<a
href="https://redirect.github.com/mozilla/bleach/issues/764">#764</a>)</li>
</ul>
<p><strong>Security fixes</strong></p>
<ul>
<li>
<p>Fix bug 2023812 / GHSA-8rfp-98v4-mmr6.</p>
<p>Fix XSS issue with sanitize_uri_value where disallowed schemes with
Unicode invisible characters wouldn't be rejected.</p>
<p>For example::</p>
<p>import bleach
payload1 = '<!-- raw HTML omitted -->Click<!-- raw HTML omitted -->'
result1 = bleach.clean(payload1)
print(repr(result1))</p>
<p>outputs::</p>
<p>'<!-- raw HTML omitted -->Click<!-- raw HTML omitted -->'</p>
<p>See the advisory for details.</p>
</li>
<li>
<p>Fix GHSA-gj48-438w-jh9v.</p>
<p>Fix issue where URI sanitization wasn't happening in formaction
attributes.</p>
<p>See the advisory for details.</p>
</li>
</ul>
<p><strong>Bug fixes</strong></p>
<ul>
<li>
<p>Add support for pypy 3.11. (<a
href="https://redirect.github.com/mozilla/bleach/issues/764">#764</a>)</p>
</li>
<li>
<p>Drop version max in tinycss2 pin. (<a
href="https://redirect.github.com/mozilla/bleach/issues/772">#772</a>)</p>
<p>This removes one of the things we had to keep checking and updating.
Users
now own the responsibility for correctness with the version of tinycss2
they're using.</p>
</li>
</ul>
<h2>Version 6.3.0 (October 27th, 2025)</h2>
<!-- raw HTML omitted -->
</blockquote>
<p>... (truncated)</p>
</details>
<details>
<summary>Commits</summary>
<ul>
<li><a
href="f0355a7af0"><code>f0355a7</code></a>
fix: fix last release date in CHANGES</li>
<li><a
href="ae4e8a2670"><code>ae4e8a2</code></a>
chore: bleach 6.4.0 and final release</li>
<li><a
href="970df58e9f"><code>970df58</code></a>
fix: uri-sanitization in formaction attributes</li>
<li><a
href="7c4867c323"><code>7c4867c</code></a>
fix: xss bypass in allowed protocol test using unicode invisible
characters</li>
<li><a
href="913ab75992"><code>913ab75</code></a>
fix: reduce redundancy in workflow jobs</li>
<li><a
href="218c15af45"><code>218c15a</code></a>
fix: rework pip caching</li>
<li><a
href="4f0b097bf8"><code>4f0b097</code></a>
fix: fix tox platform restrictions</li>
<li><a
href="e95a79d07b"><code>e95a79d</code></a>
chore: update pytest</li>
<li><a
href="91539d4e80"><code>91539d4</code></a>
Bump actions/cache from 5.0.3 to 5.0.4</li>
<li><a
href="cd47b4ce49"><code>cd47b4c</code></a>
fix: handle left-angle-bracket that's not a tag (<a
href="https://redirect.github.com/mozilla/bleach/issues/733">#733</a>)</li>
<li>Additional commits viewable in <a
href="https://github.com/mozilla/bleach/compare/v6.2.0...v6.4.0">compare
view</a></li>
</ul>
</details>
<br />


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libs/langchain/uv.lock

@@ -601,14 +601,14 @@ wheels = [
 
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+version = "6.4.0"
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 wheels = [
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+    { url = "https://files.pythonhosted.org/packages/58/9d/40b6267367182187139a4000b82a3b287d84d745bccd808e75d916920e9d/bleach-6.4.0-py3-none-any.whl", hash = "sha256:4b6b6a54fff2e69a3dde9d21cc6301220bee3c3cb792187d11403fd795031081", size = 165109, upload-time = "2026-06-05T13:01:12.504Z" },
 ]
 
 [package.optional-dependencies]