requirements: Upgrade beautifulsoup4 (bs4) from >=4.11.1 to >=4.13.4.

Author: neiljp

setup.py

@@ -108,7 +108,7 @@ def long_description():
         "urwid~=2.1.2",
         "zulip>=0.8.2,<0.9.0",  # Next release, 0.9.0, requires Python 3.9
         "urwid_readline>=0.15.1",
-        "beautifulsoup4>=4.11.1",
+        "beautifulsoup4>=4.13.4",
         "lxml~=4.9.2",
         "pygments>=2.14.0,<2.18.0",
         "typing_extensions~=4.5.0",