Use explicit Renovate Tuesday morning schedules

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

@@ -12,14 +12,14 @@
     {
       "groupName": "all patch versions",
       "matchUpdateTypes": ["patch", "digest"],
-      "schedule": ["before 8am on Tuesday"],
+      "schedule": ["* 0-7 * * 2"], // weekly, before 8am on Tuesday
       "matchPackageNames": ["!io.opentelemetry**"]
     },
     {
       // group all GitHub Actions updates into a single weekly PR
       // (must be after patch rule so that it wins for GH Action patches)
       "matchManagers": ["github-actions"],
-      "extends": ["schedule:weekly"],
+      "schedule": ["* 0-7 * * 2"], // weekly, before 8am on Tuesday
       "groupName": "github actions"
     },