Bump to 9.0.0-wip (#4057)

CHANGELOG.md

diff --git a/CHANGELOG.md b/CHANGELOG.md
index fcd3ced..78fda3d 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -1,3 +1,6 @@
+## 9.0.0-wip
+* Remove deprecated `missingCodeBlockLanguage` warning.
+
 ## 8.3.4
 * The URL for category pages now uses _category name_ instead of
   _category `displayName`_.

dartdoc_options.yaml

diff --git a/dartdoc_options.yaml b/dartdoc_options.yaml
index d5550db..7f0e62c 100644
--- a/dartdoc_options.yaml
+++ b/dartdoc_options.yaml
@@ -1,4 +1,4 @@
 dartdoc:
   linkToSource:
     root: '.'
-    uriTemplate: 'https://github.com/dart-lang/dartdoc/blob/v8.3.4/%f%#L%l%'
+    uriTemplate: 'https://github.com/dart-lang/dartdoc/blob/v9.0.0-wip/%f%#L%l%'

lib/src/version.dart

diff --git a/lib/src/version.dart b/lib/src/version.dart
index ca1e6fd..d4c9d66 100644
--- a/lib/src/version.dart
+++ b/lib/src/version.dart
@@ -1 +1 @@
-const packageVersion = '8.3.4';
+const packageVersion = '9.0.0-wip';

pubspec.yaml

diff --git a/pubspec.yaml b/pubspec.yaml
index 0e249d1..4db932f 100644
--- a/pubspec.yaml
+++ b/pubspec.yaml
@@ -1,5 +1,5 @@
 name: dartdoc
-version: 8.3.4
+version: 9.0.0-wip
 description: A non-interactive HTML documentation generator for Dart source code.
 repository: https://github.com/dart-lang/dartdoc