blast_repo fixes (dart-lang/source_span#98)

dependabot

pkgs/source_span/.github/dependabot.yml

diff --git a/pkgs/source_span/.github/dependabot.yml b/pkgs/source_span/.github/dependabot.yml
index 9735d75..c6531d4 100644
--- a/pkgs/source_span/.github/dependabot.yml
+++ b/pkgs/source_span/.github/dependabot.yml
@@ -4,7 +4,9 @@
 version: 2
 updates:
 
-- package-ecosystem: "github-actions"
-  directory: "/"
+- package-ecosystem: github-actions
+  directory: /
   schedule:
-    interval: "monthly"
+    interval: monthly
+  labels:
+    - autosubmit