[pigeon] Adds analyzer 6.x compatibility (#5418)

`analyzer` 6.0 just removes deprecated methods, so we can add support for 6.x without changes, as well as keeping 5.13 compatibility for now to minimize incompatibilities.

Fixes flutter/flutter#138616

Author: stuartmorgan-g

packages/pigeon/CHANGELOG.md

@@ -1,3 +1,7 @@
+## 13.1.2
+
+* Adds compatibilty with `analyzer` 6.x.
+
 ## 13.1.1
 
 * [kotlin] Removes unnecessary `;`s in generated code.

packages/pigeon/lib/generator_tools.dart

@@ -13,7 +13,7 @@ import 'ast.dart';
 /// The current version of pigeon.
 ///
 /// This must match the version in pubspec.yaml.
-const String pigeonVersion = '13.1.1';
+const String pigeonVersion = '13.1.2';
 
 /// Read all the content from [stdin] to a String.
 String readStdin() {

packages/pigeon/pubspec.yaml

@@ -2,13 +2,13 @@ name: pigeon
 description: Code generator tool to make communication between Flutter and the host platform type-safe and easier.
 repository: https://github.com/flutter/packages/tree/main/packages/pigeon
 issue_tracker: https://github.com/flutter/flutter/issues?q=is%3Aissue+is%3Aopen+label%3Apigeon
-version: 13.1.1 # This must match the version in lib/generator_tools.dart
+version: 13.1.2 # This must match the version in lib/generator_tools.dart
 
 environment:
   sdk: ">=2.19.0 <4.0.0"
 
 dependencies:
-  analyzer: "^5.13.0"
+  analyzer: ">=5.13.0 <7.0.0"
   args: ^2.1.0
   collection: ^1.15.0
   meta: ^1.7.0