Update dependabot.yml (dart-lang/pubspec_parse#97)

pkgs/pubspec_parse/.github/dependabot.yml

diff --git a/pkgs/pubspec_parse/.github/dependabot.yml b/pkgs/pubspec_parse/.github/dependabot.yml
index 1603cdd..cf1a705 100644
--- a/pkgs/pubspec_parse/.github/dependabot.yml
+++ b/pkgs/pubspec_parse/.github/dependabot.yml
@@ -7,3 +7,5 @@
     directory: "/"
     schedule:
       interval: "monthly"
+    labels:
+      - "autosubmit"