[url_launcher] Fix breaking change version conflict (#4000)

diff --git a/packages/url_launcher/url_launcher/CHANGELOG.md b/packages/url_launcher/url_launcher/CHANGELOG.md
index 3ff1a08..03a3f6f 100644
--- a/packages/url_launcher/url_launcher/CHANGELOG.md
+++ b/packages/url_launcher/url_launcher/CHANGELOG.md
@@ -1,3 +1,10 @@
+## 6.0.6
+
+* Require `url_launcher_platform_interface` 2.0.3. This fixes an issue
+  where 6.0.5 could fail to compile in some projects due to internal
+  changes in that version that were not compatible with earlier versions
+  of `url_launcher_platform_interface`.
+
 ## 6.0.5
 
 * Add iOS unit and UI integration test targets.
diff --git a/packages/url_launcher/url_launcher/pubspec.yaml b/packages/url_launcher/url_launcher/pubspec.yaml
index ca5dd6b..00cfc21 100644
--- a/packages/url_launcher/url_launcher/pubspec.yaml
+++ b/packages/url_launcher/url_launcher/pubspec.yaml
@@ -3,7 +3,7 @@
   web, phone, SMS, and email schemes.
 repository: https://github.com/flutter/plugins/tree/master/packages/url_launcher/url_launcher
 issue_tracker: https://github.com/flutter/flutter/issues?q=is%3Aissue+is%3Aopen+label%3A%22p%3A+url_launcher%22
-version: 6.0.5
+version: 6.0.6
 
 environment:
   sdk: ">=2.12.0 <3.0.0"
@@ -37,7 +37,7 @@
   # https://github.com/flutter/flutter/issues/46264
   url_launcher_linux: ^2.0.0
   url_launcher_macos: ^2.0.0
-  url_launcher_platform_interface: ^2.0.0
+  url_launcher_platform_interface: ^2.0.3
   url_launcher_web: ^2.0.0
   url_launcher_windows: ^2.0.0