[graphs] update dev dependencies (#1959)

diff --git a/pkgs/graphs/pubspec.yaml b/pkgs/graphs/pubspec.yaml
index bdbda2f..e25ee85 100644
--- a/pkgs/graphs/pubspec.yaml
+++ b/pkgs/graphs/pubspec.yaml
@@ -15,6 +15,6 @@
   test: ^1.21.6
 
   # For examples
-  analyzer: '>=5.2.0 <7.0.0'
+  analyzer: '>=5.2.0 <8.0.0'
   path: ^1.8.0
   pool: ^1.5.0