Remove deprecated style key for HTML templates (#11381)

CHANGES

@@ -25,6 +25,7 @@ Incompatible changes
   function.
 * #11379: Make the ``env`` argument to ``Builder`` subclasses required.
 * #11380: autosummary: Always emit grouped import exceptions.
+* #11381: Remove deprecated ``style`` key for HTML templates.
 
 Deprecated
 ----------

doc/development/templating.rst

@@ -381,22 +381,6 @@ in the future.
 
    .. versionadded:: 5.1
 
-.. data:: style
-
-   The name of the main stylesheet, as given by the theme or
-   :confval:`html_style`.
-
-   .. versionchanged:: 5.1
-
-      The theme or :confval:`html_style` are now able to specify multiple
-      stylesheets, the ``style`` key returns the last stylesheet when more than
-      one is specified.
-
-   .. deprecated:: 5.1
-
-      Use the :data:`styles` key instead, as there is no longer a single main
-      stylesheet. The ``style`` key will be removed in Sphinx 7.0.
-
 .. data:: title
 
    The title of the current document, as used in the ``<title>`` tag.

sphinx/builders/html/__init__.py

@@ -560,7 +560,6 @@ def prepare_writing(self, docnames: set[str]) -> None:
             'sphinx_version_tuple': sphinx_version,
             'docutils_version_info': docutils.__version_info__[:5],
             'styles': styles,
-            'style': styles[-1],  # xref RemovedInSphinx70Warning
             'rellinks': rellinks,
             'builder': self.name,
             'parents': [],