build: Remove qctrl-sphinx-theme (#301)

Author: leoadec

docs/conf.py

@@ -76,11 +76,6 @@
 
 # -- Options for HTML output -------------------------------------------------
 
-# The theme to use for HTML and HTML Help pages.  See the documentation for
-# a list of builtin themes.
-#
-html_theme = "qctrl_sphinx_theme"
-
 # Option to automatically generate summaries.
 autosummary_generate = True