Bump dartdoc to 0.32.3 and tighten doc quality checker (#63111)

dev/bots/docs.sh

@@ -37,7 +37,7 @@ function script_location() {
 
 function generate_docs() {
     # Install and activate dartdoc.
-    "$PUB" global activate dartdoc 0.32.1
+    "$PUB" global activate dartdoc 0.32.3
 
     # This script generates a unified doc set, and creates
     # a custom index.html, placing everything into dev/docs/doc.

dev/tools/dartdoc_checker.dart

@@ -85,14 +85,9 @@ void checkForUnresolvedDirectives(String htmlOutputPath) {
 
 int _scanFile(File file) {
   assert(path.extension(file.path) == 'html');
-  Iterable<String> matches = _pattern.allMatches(file.readAsStringSync())
+  final Iterable<String> matches = _pattern.allMatches(file.readAsStringSync())
       .map((RegExpMatch m ) => m.group(0));
 
-  // TODO(goderbauer): Remove this exception when https://github.com/dart-lang/dartdoc/issues/1945 is fixed.
-  matches = matches
-      .where((String m) => m != '{@inject-html}')
-      .where((String m) => m != '{@end-inject-html}');
-
   if (matches.isNotEmpty) {
     stderr.writeln('Found unresolved dartdoc directives in ${file.path}:');
     for (final String match in matches) {