Fix search and version menu in docs

The `html_theme_path` option should not be used any more with
sphinx-rtd-theme since it switches off the theme's ability to
automatically enable the sphinxcontrib-jquery extension, i.e.
jQuery is not loaded in the web pages when building the docs with
Sphinx >=6.

xref: readthedocs/sphinx_rtd_theme#1434 (comment)

Also replace the deprecated `canonical_url` theme option with
Sphinx's `html_baseurl`.

xref: https://sphinx-rtd-theme.readthedocs.io/en/stable/configuring.html#confval-canonical_url

doc/source/conf.py

@@ -14,8 +14,6 @@
 import os
 import sys
 
-import sphinx_rtd_theme
-
 # Set GALAXY_DOCS_SKIP_VIEW_CODE=1 to skip embedding highlighted source
 # code into docs.
 SKIP_VIEW_CODE = os.environ.get("GALAXY_DOCS_SKIP_VIEW_CODE", False) == "1"
@@ -161,11 +159,10 @@ def setup(app):
     "collapse_navigation": False,
     "display_version": True,
     "navigation_depth": 2,
-    "canonical_url": "https://docs.galaxyproject.org/en/master/",
 }
 
 # Add any paths that contain custom themes here, relative to this directory.
-html_theme_path = [sphinx_rtd_theme.get_html_theme_path()]
+# html_theme_path = []
 
 # The name for this set of Sphinx documents.  If None, it defaults to
 # "<project> v<release> documentation".
@@ -174,6 +171,8 @@ def setup(app):
 # A shorter title for the navigation bar.  Default is the same as html_title.
 # html_short_title = None
 
+html_baseurl = "https://docs.galaxyproject.org/en/master/"
+
 # The name of an image file (relative to this directory) to place at the top
 # of the sidebar.
 # html_logo = None