Group golang dependabot updates (#2613)

This should reduce some CI pressure, at the risk of increasing the
PR size under review.

For PRs that update graphql/atlas/any library that then requires
changing generated code, we would need to run `make generate` on top of
the large diff. But, even this should be less frequent now, since
instead of having to do this for 1 PR that changes gql and 1 PR that
changes atlas we can do both in the same PR. If the diff size becomes
too large we could exclude these, just like we do with the golang/x
ones.

Signed-off-by: Mihai Maruseac <[email protected]>

Author: mihaimaruseac

.github/dependabot.yml

@@ -5,6 +5,15 @@ updates:
     directory: "/"
     schedule:
       interval: weekly
+    groups:
+      gomod:
+        patterns:
+          - "*"
+        exclude-patterns:
+          - "golang.org/x/*"
+      golang-x:
+        patterns:
+          - "golang.org/x/*"
 
   # Maintain dependencies for GitHub Actions.
   - package-ecosystem: "github-actions"