don't run fix-bazel-cache on PRs (#16377)

I'm annoyed at how slow it runs. The hourly cron should be good enough.

azure-cron.yml

@@ -28,7 +28,34 @@ trigger: none
 #  always: true
 
 jobs:
-  - template: ci/fix-bazel-cache.yml
+  - job: fix_bazel_cache
+    timeoutInMinutes: 120
+    pool:
+      name: 'ubuntu_20_04'
+      demands: assignment -equals default
+    steps:
+      - checkout: self
+      - bash: ci/dev-env-install.sh
+        displayName: 'Build/Install the Developer Environment'
+      - template: bash-lib.yml
+        parameters:
+          var_name: bash-lib
+      - bash: |
+          set -euo pipefail
+          eval "$(dev-env/bin/dade assist)"
+
+          bazel build //ci/cron:cron
+
+          key=$(mktemp)
+          cleanup="rm -rf $key ~/.config/gcloud"
+          trap "$cleanup" EXIT
+          echo "$GCRED" > $key
+          gcloud auth activate-service-account --key-file=$key
+          export BOTO_CONFIG=/dev/null
+          ./bazel-bin/ci/cron/cron bazel-cache --age 75 --delete --cache-suffix '**'
+        env:
+          GCRED: $(GOOGLE_APPLICATION_CREDENTIALS_CONTENT)
+      - template: tell-slack-failed.yml
 
   - job: docker_image
     timeoutInMinutes: 60

ci/build.yml

@@ -3,8 +3,6 @@
 
 jobs:
 
-- template: fix-bazel-cache.yml
-
 - job: git_sha
   pool:
     name: 'ubuntu_20_04'

ci/fix-bazel-cache.yml

@@ -1,33 +0,0 @@
-# Copyright (c) 2023 Digital Asset (Switzerland) GmbH and/or its affiliates. All rights reserved.
-# SPDX-License-Identifier: Apache-2.0
-
-jobs:
-- job: fix_bazel_cache
-  timeoutInMinutes: 120
-  condition: eq(variables['System.PullRequest.IsFork'], 'False')
-  pool:
-    name: 'ubuntu_20_04'
-    demands: assignment -equals default
-  steps:
-    - checkout: self
-    - bash: ci/dev-env-install.sh
-      displayName: 'Build/Install the Developer Environment'
-    - template: bash-lib.yml
-      parameters:
-        var_name: bash-lib
-    - bash: |
-        set -euo pipefail
-        eval "$(dev-env/bin/dade assist)"
-
-        bazel build //ci/cron:cron
-
-        key=$(mktemp)
-        cleanup="rm -rf $key ~/.config/gcloud"
-        trap "$cleanup" EXIT
-        echo "$GCRED" > $key
-        gcloud auth activate-service-account --key-file=$key
-        export BOTO_CONFIG=/dev/null
-        ./bazel-bin/ci/cron/cron bazel-cache --age 75 --delete --cache-suffix '**'
-      env:
-        GCRED: $(GOOGLE_APPLICATION_CREDENTIALS_CONTENT)
-    - template: tell-slack-failed.yml