tools: remove unsupported cooldown from Dependabot config

PR-URL: #60747
Refs: https://docs.github.com/en/code-security/dependabot/working-with-dependabot/dependabot-options-reference#configuration-of-cooldown
Reviewed-By: Michaël Zasso <[email protected]>
Reviewed-By: Ulises Gascón <[email protected]>
Reviewed-By: Colin Ihrig <[email protected]>
Reviewed-By: Luigi Pinca <[email protected]>

Author: aduh95

.github/dependabot.yml

@@ -6,10 +6,6 @@ updates:
     directory: /
     schedule:
       interval: monthly
-    cooldown:
-      semver-major-days: 5
-      semver-minor-days: 5
-      semver-patch-days: 5
     commit-message:
       prefix: meta
     open-pull-requests-limit: 10