Remove intl fork

The workaround no longer seems to be required with the latest version of
flutter.

pubspec.lock

@@ -491,12 +491,10 @@ packages:
   intl:
     dependency: "direct main"
     description:
-      path: "."
-      ref: HEAD
-      resolved-ref: bdad67e32fedd828ca61004b7007fd7a07087635
-      url: "https://github.com/GitJournal/intl.git"
-    source: git
-    version: "0.17.0-dev"
+      name: intl
+      url: "https://pub.dartlang.org"
+    source: hosted
+    version: "0.16.1"
   io:
     dependency: transitive
     description:

pubspec.yaml

@@ -7,8 +7,7 @@ dependencies:
     sdk: flutter
   flutter_localizations:
     sdk: flutter
-  intl:
-    git: https://github.com/GitJournal/intl.git
+  intl: ^0.16.1
   path: ^1.6.2
   uuid: ^2.0.1
   yaml: ^2.2.0
@@ -70,8 +69,6 @@ dev_dependencies:
   benchmark_harness: any
 
 dependency_overrides:
-  intl:
-    git: https://github.com/GitJournal/intl.git
   markdown:
     git: https://github.com/GitJournal/markdown.git