build(docs): Remove settings leftover from sphinx-releases

Author: tony

doc/conf.py

@@ -32,11 +32,6 @@
     'sphinx_issues',
 ]
 
-releases_unstable_prehistory = True
-releases_document_name = ["history"]
-releases_issue_uri = "https://github.com/tmux-python/libtmux/issues/%s"
-releases_release_uri = "https://github.com/tmux-python/libtmux/tree/v%s"
-
 issues_github_path = about['__github__'].replace('https://github.com/', '')
 
 templates_path = ['_templates']