Update dependabot.yml to remove reviewers option

Dependabot is now posting this comment as a warning:

The reviewers field in the dependabot.yml file will be removed soon. Please use the code owners file to specify reviewers for Dependabot PRs. For more information, see this blog post.

Author: shenxianpeng

.github/dependabot.yml

@@ -10,8 +10,6 @@ updates:
     directory: /
     schedule:
       interval: "weekly"
-    reviewers:
-      - "shenxianpeng"
     groups:
       docker:
         patterns:
@@ -21,8 +19,6 @@ updates:
     directory: /
     schedule:
       interval: "weekly"
-    reviewers:
-      - "shenxianpeng"
     groups:
       actions:
         patterns: