Use explicit Renovate Tuesday morning schedules (#441)

This switches Renovate scheduling to an explicit Tuesday morning cron schedule:

`* 0-7 * * 2`

The goal is to preserve the existing weekly timing while moving away from deprecated older schedule syntax and reducing repeated same-day Renovate churn.

Ported from open-telemetry/semantic-conventions#3576

Author: trask

.github/renovate.json5

@@ -16,7 +16,7 @@
         'patch',
       ],
       schedule: [
-        'before 8am on Tuesday',
+        '* 0-7 * * 2', // weekly, before 8am on Tuesday
       ],
     },
     {
@@ -25,8 +25,8 @@
       matchManagers: [
         'github-actions',
       ],
-      extends: [
-        'schedule:weekly',
+      schedule: [
+        '* 0-7 * * 2', // weekly, before 8am on Tuesday
       ],
       groupName: 'github actions',
     },