Re-enable Dependabot and the scheduled upgrade check for v3-4-test (#75276)

#74798 re-enabled the backport automation for v3-4-test after the 3.4.0 beta fast-forward phase but deliberately left Dependabot and the scheduled CI upgrade check paused to avoid dependency and CI churn during the RC phase. Re-enable them now, reversing the pauses added in #74327:

- Remove the `open-pull-requests-limit: 0` pause from the seven v3-4-test Dependabot update groups in `.github/dependabot.yml` (the manual Go-module pause is left untouched).
- Uncomment the `schedule` cron in `.github/workflows/scheduled-upgrade-check-v3-4-test.yml`.

related: #74327, #74798

Co-authored-by: Claude <noreply@anthropic.com>

.github/dependabot.yml

@@ -46,9 +46,6 @@ updates:
       # Check for updates to GitHub Actions every week
       interval: "weekly"
     target-branch: v3-4-test
-    # Paused while v3-4-test is fast-forwarded to main for the 3.4.0 betas - remove when the
-    # 3.4.0 RCs start (see "Beta releases" in dev/README_RELEASE_AIRFLOW.md).
-    open-pull-requests-limit: 0
     groups:
       github-actions-updates:
         patterns:
@@ -268,9 +265,6 @@ updates:
     schedule:
       interval: daily
     target-branch: v3-4-test
-    # Paused while v3-4-test is fast-forwarded to main for the 3.4.0 betas - remove when the
-    # 3.4.0 RCs start (see "Beta releases" in dev/README_RELEASE_AIRFLOW.md).
-    open-pull-requests-limit: 0
     groups:
       pip-dependency-updates:
         patterns:
@@ -284,9 +278,6 @@ updates:
     schedule:
       interval: "weekly"
     target-branch: v3-4-test
-    # Paused while v3-4-test is fast-forwarded to main for the 3.4.0 betas - remove when the
-    # 3.4.0 RCs start (see "Beta releases" in dev/README_RELEASE_AIRFLOW.md).
-    open-pull-requests-limit: 0
     groups:
       3-4-core-ui-package-updates:
         patterns:
@@ -306,9 +297,6 @@ updates:
     schedule:
       interval: "weekly"
     target-branch: v3-4-test
-    # Paused while v3-4-test is fast-forwarded to main for the 3.4.0 betas - remove when the
-    # 3.4.0 RCs start (see "Beta releases" in dev/README_RELEASE_AIRFLOW.md).
-    open-pull-requests-limit: 0
     groups:
       3-4-auth-ui-package-updates:
         patterns:
@@ -337,9 +325,6 @@ updates:
     schedule:
       interval: "weekly"
     target-branch: v3-4-test
-    # Paused while v3-4-test is fast-forwarded to main for the 3.4.0 betas - remove when the
-    # 3.4.0 RCs start (see "Beta releases" in dev/README_RELEASE_AIRFLOW.md).
-    open-pull-requests-limit: 0
     groups:
       3-4-registry-package-updates:
         patterns:
@@ -359,9 +344,6 @@ updates:
     schedule:
       interval: "weekly"
     target-branch: v3-4-test
-    # Paused while v3-4-test is fast-forwarded to main for the 3.4.0 betas - remove when the
-    # 3.4.0 RCs start (see "Beta releases" in dev/README_RELEASE_AIRFLOW.md).
-    open-pull-requests-limit: 0
     groups:
       3-4-ui-plugin-template-package-updates:
         patterns:
@@ -380,9 +362,6 @@ updates:
     schedule:
       interval: "weekly"
     target-branch: v3-4-test
-    # Paused while v3-4-test is fast-forwarded to main for the 3.4.0 betas - remove when the
-    # 3.4.0 RCs start (see "Beta releases" in dev/README_RELEASE_AIRFLOW.md).
-    open-pull-requests-limit: 0
     groups:
       3-4-uv-dependency-updates:
         patterns:

.github/workflows/scheduled-upgrade-check-v3-4-test.yml

@@ -18,12 +18,9 @@
 ---
 name: "[v3-4-test] Scheduled CI upgrade check"
 on:  # yamllint disable-line rule:truthy
-  # Schedule paused while v3-4-test is fast-forwarded to main for the 3.4.0 betas - upgrades
-  # land on main and reach v3-4-test with the next fast-forward. Re-enable when the 3.4.0
-  # RCs start (see "Beta releases" in dev/README_RELEASE_AIRFLOW.md).
-  # schedule:
-  #   # Tue, Thu at 06:00 UTC — the days main does not run, so the two never overlap.
-  #   - cron: '0 6 * * 2,4'
+  schedule:
+    # Tue, Thu at 06:00 UTC — the days main does not run, so the two never overlap.
+    - cron: '0 6 * * 2,4'
   workflow_dispatch:
 permissions:
   contents: write