Update rdoc to v6.16

Interface of `RDoc::AnyMethod#start_collecting_tokens` has been changed
from rdoc v6.16.

Author: ksss

Gemfile

@@ -16,7 +16,7 @@ gem "json-schema"
 gem "goodcheck"
 gem 'digest'
 gem 'tempfile'
-gem "rdoc"
+gem "rdoc", "~> 6.16"
 gem "fileutils"
 gem "raap"
 gem "activesupport", "~> 7.0"

Gemfile.lock

@@ -105,7 +105,7 @@ GEM
     rb-fsevent (0.11.2)
     rb-inotify (0.11.1)
       ffi (~> 1.0)
-    rdoc (6.15.1)
+    rdoc (6.16.0)
       erb
       psych (>= 4.0.0)
       tsort
@@ -217,7 +217,7 @@ DEPENDENCIES
   rake-compiler
   rbs!
   rbs-amber!
-  rdoc
+  rdoc (~> 6.16)
   rspec
   rubocop
   rubocop-on-rbs

lib/rdoc/discover.rb

@@ -1,7 +1,7 @@
 # frozen_string_literal: true
 
 begin
-  gem 'rdoc', '~> 6.13'
+  gem 'rdoc', '~> 6.16'
   require 'rdoc_plugin/parser'
   module RDoc
     class Parser

lib/rdoc_plugin/parser.rb

@@ -76,7 +76,7 @@ def parse_method_decl(decl:, context:, outer_name: nil)
         method.visibility = decl.visibility
         method.call_seq = decl.overloads.map {|overload| "#{decl.name.to_s}#{overload.method_type.to_s}" }.join("\n")
         if loc = decl.location
-          method.start_collecting_tokens
+          method.start_collecting_tokens(:ruby)
           method.add_token({ line_no: 1, char_no: 1, kind: :on_comment, text: "# File #{@top_level.relative_name}, line(s) #{loc.start_line}:#{loc.end_line}\n" })
           method.add_token({ line_no: 1, char_no: 1, text: loc.source })
           method.line = loc.start_line

stdlib/rdoc/0/rdoc.rbs

@@ -84,7 +84,7 @@ module RDoc
     # -->
     # Starts collecting tokens
     #
-    def collect_tokens: () -> void
+    def collect_tokens: (Symbol) -> void
 
     # <!--
     #   rdoc-file=lib/rdoc/token_stream.rb