build: add pull requests limit for dependabot (#5299)

Co-authored-by: Boquan Fang <bqfang@amazon.com>

Author: boquan-fang

.github/dependabot.yml

@@ -35,3 +35,4 @@ updates:
       - "/bindings/rust/extended"
     schedule:
       interval: "daily"
+    open-pull-requests-limit: 10