Prepare analyzer_plugin 0.11.3

My plan is to checkout the SDK when analyzer 6.0.0 was published,
then cherry-pick this commit, and publish analyzer_plugin.

In a test run, the package analyzes cleanly and all tests pass.

Bug: https://github.com/dart-lang/sdk/issues/52769
Change-Id: I10661dd665c612eeb82977bdf2f8432e022044b6
Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/317802
Reviewed-by: Konstantin Shcheglov <scheglov@google.com>
Commit-Queue: Samuel Rawlins <srawlins@google.com>

pkg/analyzer_plugin/CHANGELOG.md

@@ -1,3 +1,7 @@
+## 0.11.3
+
+- Support version `6.x` of the `analyzer` package
+
 ## 0.11.2
 
 - Support version `5.x` of the `analyzer` package

pkg/analyzer_plugin/pubspec.yaml

@@ -1,16 +1,16 @@
 name: analyzer_plugin
 description: A framework and support code for building plugins for the analysis server.
-version: 0.11.2
+version: 0.11.3
 repository: https://github.com/dart-lang/sdk/tree/main/pkg/analyzer_plugin
 
 environment:
-  sdk: '>=2.17.0 <3.0.0'
+  sdk: '^3.0.0'
 
 dependencies:
-  analyzer: ^5.0.0
+  analyzer: ^6.0.0
   collection: ^1.15.0
   dart_style: ^2.2.1
-  pub_semver: ^2.0.0
+  pub_semver: ^2.1.0
   yaml: ^3.1.0
 
 # We use 'any' version constraints here as we get our package versions from