Docs: drop sphinxcontrib-video

The epub build broke on sphinx-design's dropdowns after moving to the
upstream release, which registers node handlers under the `epub` builder
name and so suppresses Sphinx's fallback to the `html` handlers.

The extension had a single call site, so render that video with a plain
`<video>` tag instead of working around the conflict.

Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01Kq5hTeCe1JedqHAF1UEGvt

Author: claude

docs/conf.py

@@ -32,7 +32,6 @@
     "sphinx.ext.extlinks",
     "sphinx.ext.intersphinx",
     "sphinxcontrib.httpdomain",
-    "sphinxcontrib.video",
     "sphinxemoji.sphinxemoji",
     "sphinxext.opengraph",
 ]

docs/user/science.rst

@@ -72,8 +72,14 @@ Here's a brief overview of some :doc:`features </reference/features>` that peopl
 
     Build and publish your project for every change made through Git (GitHub, GitLab, Bitbucket etc). Preview changes via pull requests. Receive notifications when something is wrong. How does this work? Have a look at this video:
 
-    .. video:: https://anti-pattern-sphinx-video-downloader.readthedocs.io/_static/videos/enable-pull-request-builders.mp4
-       :height: 300
+    .. raw:: html
+
+        <video controls height="300" preload="auto">
+          <source
+            src="https://anti-pattern-sphinx-video-downloader.readthedocs.io/_static/videos/enable-pull-request-builders.mp4"
+            type="video/mp4"
+          >
+        </video>
 
 .. dropdown:: 💬 Collaboration and community
 

requirements/docs.in

@@ -27,4 +27,3 @@ sphinx-copybutton
 # Markdown
 myst_parser
 
-sphinxcontrib-video

requirements/docs.txt

@@ -116,7 +116,6 @@ sphinx==8.2.3
     #   sphinx-tabs
     #   sphinxcontrib-httpdomain
     #   sphinxcontrib-jquery
-    #   sphinxcontrib-video
     #   sphinxemoji
     #   sphinxext-opengraph
 sphinx-autobuild==2025.8.25
@@ -153,8 +152,6 @@ sphinxcontrib-qthelp==2.0.0
     # via sphinx
 sphinxcontrib-serializinghtml==2.0.0
     # via sphinx
-sphinxcontrib-video==0.4.2
-    # via -r requirements/docs.in
 sphinxemoji==0.3.2
     # via -r requirements/docs.in
 sphinxext-opengraph==0.13.0