DOC: fix version switcher [skip actions] [skip appveyor] [skip azp]

Author: jklymak

doc/conf.py

@@ -324,7 +324,7 @@ def matplotlib_reduced_latex_scraper(block, block_vars, gallery_conf,
     "collapse_navigation": not is_release_build,
     "show_prev_next": False,
     "switcher": {
-        "json_url": "https://matplotlib.org/%3Cspan%20class="x x-first x-last">en/devdocs/_static/switcher.json",
+        "json_url": "https://matplotlib.org/devdocs/_static/switcher.json",
         "url_template": "https://matplotlib.org/{version}/"
     },
     "navbar_end": ["version-switcher", "mpl_icon_links"]