test-documentation: Remove unneeded HTML validation exemptions.

Signed-off-by: Anders Kaseorg <anders@zulip.com>

tools/documentation.vnufilter

@@ -3,7 +3,6 @@
 Consider using the “h1” element as a top-level heading only \(all “h1” elements are treated as top-level headings by many screen readers and other tools\)\.
 Document uses the Unicode Private Use Area\(s\), which should not be used in publicly exchanged documents\. \(Charmod C073\)
 Section lacks heading\. Consider using “h2”-“h6” elements to add identifying headings to all sections, or else use a “div” element instead for any cases where no heading is needed\.
-Stray end tag “input”\.
 
 # Opinionated informational messages.
 

tools/documentation_crawler/documentation_crawler/spiders/common/spiders.py

@@ -45,10 +45,6 @@ VNU_IGNORE = [
     # Real errors that should be fixed.
     r"Attribute “markdown” not allowed on element “div” at this point\.",
     r"No “p” element in scope but a “p” end tag seen\.",
-    (
-        r"Element “div” not allowed as child of element “ul” in this context\."
-        r" \(Suppressing further errors from this subtree\.\)"
-    ),
     # Opinionated informational messages.
     r"Trailing slash on void elements has no effect and interacts badly with unquoted attribute values\.",
 ]