chore: remove dependabot configuration file and update CODEOWNERS (#1550)

Author: h4rkl

.github/CODEOWNERS

@@ -16,7 +16,6 @@
 # themselves, so they always need maintainer sign-off.
 /.github/                       @h4rkl @ZYJLiu
 /.github/workflows/             @h4rkl @ZYJLiu
-/.github/dependabot.yml         @h4rkl @ZYJLiu
 /.github/CODEOWNERS             @h4rkl @ZYJLiu
 
 # Secrets scanning and disclosure policy.