chore(repo): update renovate schedule

renovate.json5

@@ -94,8 +94,19 @@
   ],
   // Never rebase the branch or update it unless manually requested to avoid noisy PR emails
   rebaseWhen: 'never',
-  // Note: Timezone for the schedule is specified as UTC
-  schedule: ['every weekday before 11am'],
+  /**
+   * Run every Monday and Thursday between midnight at 11 AM (in UTC)
+   *
+   * Monday and Thursday were chosen to:
+   * - Keep the `minimumReleaseAge` value in mind (three days)
+   * - Prevent spikes/bursts of PRs from Renovate on a single day of the week
+   *
+   * We use cron syntax here as it's more deterministic/easier to provide a value that we know that Renovate will
+   * accept, compared to the natural language syntax which is (subjectively) trickier to test without merging first.
+   *
+   * {@see https://crontab.guru} for debugging cron schedules
+   */
+  schedule: ['* 0-11 * * 1,4'],
   /**
    * Ensure semantic commits are enabled for commits + PR titles.
    *