chore(deps): use widen versioning strategy with dependabot

As simple-github is a library, we want it to run with as large a range
as possible.

Author: ahal

.github/dependabot.yml

@@ -4,6 +4,7 @@ updates:
     directory: "/"
     schedule:
       interval: "monthly"
+    versioning-strategy: widen
     groups:
       minor-and-patch:
         applies-to: version-updates