BUG - Clear alt_text in conf.py (#1471)

* comment out alt_text in conf.py

* set alt_text to empty string

* remove alt_text from conf.py

Author: gabalafou

docs/conf.py

@@ -161,7 +161,6 @@
     "logo": {
         "text": "PyData Theme",
         "image_dark": "_static/logo-dark.svg",
-        "alt_text": "PyData Theme",
     },
     "use_edit_page_button": True,
     "show_toc_level": 1,