ci: scheduled workflows run on the cron lane runner

astra, heartbeat, housekeeping, sync, update and venture move to runs-on: cron
(green-tea-runner-cron), so they never queue ahead of deploys on the main runner.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01VVFi3wvLWKaEkpDw6eLnQC

.github/workflows/astra.yml

@@ -13,7 +13,7 @@ concurrency:
 jobs:
   plan:
     if: vars.TIME_ASTRA == 'on'
-    runs-on: ubuntu-latest
+    runs-on: cron
     timeout-minutes: 10
     steps:
       - uses: actions/checkout@v5

.github/workflows/heartbeat.yml

@@ -23,7 +23,7 @@ jobs:
       (github.event_name != 'issue_comment' || (github.event.issue.pull_request && github.event.comment.user.login != 'gitea-actions' &&
         (startsWith(github.event.comment.body, '**Approve') || startsWith(github.event.comment.body, 'Approve') ||
          startsWith(github.event.comment.body, '**Object') || startsWith(github.event.comment.body, 'Object'))))
-    runs-on: ubuntu-latest
+    runs-on: cron
     timeout-minutes: 55   # workers can overlap inside one job now (#75); under the hourly cadence, and the concurrency group queues the next run
     steps:
       - uses: actions/checkout@v5

.github/workflows/housekeeping.yml

@@ -11,7 +11,7 @@ concurrency:
   cancel-in-progress: false
 jobs:
   sweep:
-    runs-on: ubuntu-latest
+    runs-on: cron
     timeout-minutes: 10
     steps:
       - uses: actions/checkout@v5

.github/workflows/sync.yml

@@ -20,7 +20,7 @@ concurrency:
   cancel-in-progress: false
 jobs:
   sync:
-    runs-on: ubuntu-latest
+    runs-on: cron
     timeout-minutes: 10
     steps:
       - uses: actions/checkout@v5

.github/workflows/update.yml

@@ -12,7 +12,7 @@ permissions:
 jobs:
   update:
     if: github.repository != (vars.TIME_UPSTREAM || 'teahubxyz/time')
-    runs-on: ubuntu-latest
+    runs-on: cron
     timeout-minutes: 3
     env:
       UPSTREAM: ${{ vars.TIME_UPSTREAM || 'teahubxyz/time' }}

.github/workflows/venture.yml

@@ -27,7 +27,7 @@ concurrency:
   cancel-in-progress: false
 jobs:
   tick:
-    runs-on: ubuntu-latest
+    runs-on: cron
     timeout-minutes: 40
     steps:
       - uses: actions/checkout@v5