build(deps): update shibuya requirement from <2025.9.22 (#4871)

Updates the requirements on
[shibuya](https://github.com/lepture/shibuya) to permit the latest
version.
<details>
<summary>Release notes</summary>
<p><em>Sourced from <a
href="https://github.com/lepture/shibuya/releases">shibuya's
releases</a>.</em></p>
<blockquote>
<h2>2025.9.25</h2>
<h3>   🐞 Bug Fixes</h3>
<ul>
<li>Dark theme support for sphinxcontrib-mermaid extension  -  by <a
href="https://github.com/lepture"><code>@​lepture</code></a> <a
href="https://github.com/lepture/shibuya/commit/8c6e8b7"><!-- raw HTML
omitted -->(8c6e8)<!-- raw HTML omitted --></a></li>
<li>Prevent building error when toc is empty  -  by <a
href="https://github.com/lepture"><code>@​lepture</code></a> <a
href="https://github.com/lepture/shibuya/commit/cf082e1"><!-- raw HTML
omitted -->(cf082)<!-- raw HTML omitted --></a></li>
<li>Improve SponsorsDirective  -  by <a
href="https://github.com/lepture"><code>@​lepture</code></a> <a
href="https://github.com/lepture/shibuya/commit/f623d24"><!-- raw HTML
omitted -->(f623d)<!-- raw HTML omitted --></a></li>
<li>Update sponsors style  -  by <a
href="https://github.com/lepture"><code>@​lepture</code></a> <a
href="https://github.com/lepture/shibuya/commit/214dde7"><!-- raw HTML
omitted -->(214dd)<!-- raw HTML omitted --></a></li>
</ul>
<h5>    <a
href="https://github.com/lepture/shibuya/compare/2025.9.24...2025.9.25">View
changes on GitHub</a></h5>
</blockquote>
</details>
<details>
<summary>Changelog</summary>
<p><em>Sourced from <a
href="https://github.com/lepture/shibuya/blob/main/docs/changelog.rst">shibuya's
changelog</a>.</em></p>
<blockquote>
<h2>2025.9.25</h2>
<ul>
<li><strong>Fix</strong>: Add dark theme support for
sphinxcontrib-mermaid extension.</li>
<li><strong>Fix</strong>: Fix building error when toc is empty, via
:issue:<code>91</code>.</li>
<li><strong>Fix</strong>: Improve <code>shibuya.sponsors</code>
extension.</li>
</ul>
<h2>2025.9.24</h2>
<ul>
<li><strong>New</strong>: add a <code>shibuya.sponsors</code>
extension.</li>
<li><strong>Fix</strong>: remove useless pygments css files.</li>
<li><strong>Fix</strong>: hide username when repository name is too
long.</li>
<li><strong>Fix</strong>: update head backrop blur style.</li>
<li><strong>Fix</strong>: update base template's block
<code>theme_scripts</code> to <code>themescripts</code>.</li>
</ul>
<h2>2025.9.23</h2>
<ul>
<li><strong>Fix</strong>: fix <code>pageurl</code> context when it is
<code>None</code>, via :issue:<code>90</code>.</li>
</ul>
<h2>2025.9.22</h2>
<ul>
<li><strong>Refactor</strong>: Update python code structure.</li>
<li><strong>Fix</strong>: Support for Pygments extension, via
:issue:<code>89</code>.</li>
<li><strong>Fix</strong>: Build pygments styles dynamically.</li>
<li><strong>Fix</strong>: Fix text overflow for math block and pre.</li>
<li><strong>Fix</strong>: Fix style for buysellads.</li>
</ul>
<h2>2025.8.16</h2>
<ul>
<li><strong>Update</strong>: Use tailwindcss v4.</li>
<li><strong>Fix</strong>: Improve copybutton's position in code
blocks.</li>
<li><strong>Fix</strong>: Improve style for sphinx-contributors.</li>
<li><strong>Fix</strong>: Fix JS errors when scrolling on landing
page.</li>
</ul>
<h2>2025.7.24</h2>
<ul>
<li><strong>Fix</strong>: Improve accessibility for nav links, you can
now using keyboard to open sub nav links.</li>
<li><strong>Fix</strong>: Update sphinx-design's style for
iconify-icon.</li>
</ul>
<h2>2025.7.14</h2>
<ul>
<li><strong>New</strong>: Add <code>data-accent-color</code> style for
:ref:<code>sphinx-iconify</code>.</li>
<li><strong>New</strong>: Add <code>outline</code> variant style for
sphinx-design's tab-set.</li>
</ul>
<!-- raw HTML omitted -->
</blockquote>
<p>... (truncated)</p>
</details>
<details>
<summary>Commits</summary>
<ul>
<li><a
href="https://github.com/lepture/shibuya/commit/e3832e3c918b98af656b9dec7ace8cff1f2d2e26"><code>e3832e3</code></a>
chore: release 2025.9.25</li>
<li><a
href="https://github.com/lepture/shibuya/commit/fb9446bf20620399979bb070c6b1f90425b797f7"><code>fb9446b</code></a>
docs: update changelog</li>
<li><a
href="https://github.com/lepture/shibuya/commit/b61847f079bdca603e8bf3b95d0d091d4a43a4a7"><code>b61847f</code></a>
chore: ruff format</li>
<li><a
href="https://github.com/lepture/shibuya/commit/4cea3db8e525b9d8abf37ad543ad1b01703ad1a9"><code>4cea3db</code></a>
docs: add a sponsors page</li>
<li><a
href="https://github.com/lepture/shibuya/commit/214dde71af2c91fd4f893727b2db10166d798a85"><code>214dde7</code></a>
fix: update sponsors style</li>
<li><a
href="https://github.com/lepture/shibuya/commit/f623d24b8e9201424e03e5ce06d93ba0b8e439ed"><code>f623d24</code></a>
fix: improve SponsorsDirective</li>
<li><a
href="https://github.com/lepture/shibuya/commit/cf082e104bba64b89bc8d47b9ed9968d423fd6e6"><code>cf082e1</code></a>
fix: prevent building error when toc is empty</li>
<li><a
href="https://github.com/lepture/shibuya/commit/8c6e8b727d0d573fa86d4340ccd18cc1ec302048"><code>8c6e8b7</code></a>
fix: dark theme support for sphinxcontrib-mermaid extension</li>
<li><a
href="https://github.com/lepture/shibuya/commit/0055315f2d907cd37b33e96c308905eb5537330e"><code>0055315</code></a>
chore: release 2025.9.24</li>
<li><a
href="https://github.com/lepture/shibuya/commit/53d76dcf077add220b955ccfac334dd3611796d7"><code>53d76dc</code></a>
fix: update block theme_scripts to themescripts</li>
<li>Additional commits viewable in <a
href="https://github.com/lepture/shibuya/compare/2023.2.23a1...2025.9.25">compare
view</a></li>
</ul>
</details>
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</details>

<!-- CURSOR_SUMMARY -->
---

> [!NOTE]
> Removes the version cap on `shibuya` in `requirements-docs.txt` to
allow the latest release.
> 
> <sup>Written by [Cursor
Bugbot](https://cursor.com/dashboard?tab=bugbot) for commit
cbacc63. This will update automatically
on new commits. Configure
[here](https://cursor.com/dashboard?tab=bugbot).</sup>
<!-- /CURSOR_SUMMARY -->

---------

Signed-off-by: dependabot[bot] <[email protected]>
Co-authored-by: dependabot[bot] <49699333+dependabot[bot]@users.noreply.github.com>
Co-authored-by: Ivana Kellyer <[email protected]>

Author: dependabot[bot]

requirements-docs.txt

@@ -1,5 +1,5 @@
 gevent
-shibuya<2025.9.22
+shibuya
 sphinx<8.2
 sphinx-autodoc-typehints[type_comments]>=1.8.0
 typing-extensions