CI: Add a scheduled dependency cache job

FYI: This job will be then used by 'buildkite-ci' and configured as a
'buildkite_pipeline_schedule' with a weekly frequency.

.buildkite/commands/cache-dependencies.sh

@@ -0,0 +1,29 @@
+#!/bin/bash
+
+set -euo pipefail
+
+echo "--- :rubygems: Setting up Gems"
+install_gems
+
+echo "--- :closed_lock_with_key: Installing Secrets"
+bundle exec fastlane run configure_apply
+
+echo "--- 🛠 Download Mobile App Dependencies [Assemble Jetpack App]"
+./gradlew assembleJetpackJalapenoDebug
+
+echo "--- 🧹 Download Lint Dependencies [Lint Jetpack App]"
+./gradlew lintJetpackJalapenoDebug
+
+echo "--- 🧹 Download Detekt Dependencies [Run Detekt]"
+./gradlew detekt
+
+echo "--- 🧹 Download Checkstyle Dependencies [Run Checkstyle]"
+./gradlew checkstyle
+
+echo "--- 🧪 Download Unit Test Dependencies [Assemble Unit Tests]"
+./gradlew assembleJetpackJalapenoDebugUnitTest libs:processors:testClasses libs:image-editor:assembleDebugUnitTest libs:fluxc:assembleDebugUnitTest libs:login:assembleDebugUnitTest
+
+echo "--- 🧪 Download Android Test Dependencies [Assemble Android Tests]"
+./gradlew assembleJetpackJalapenoDebugAndroidTest
+
+save_gradle_dependency_cache

.buildkite/schedules/dependency-cache.yml

@@ -0,0 +1,12 @@
+# yaml-language-server: $schema=https://raw.githubusercontent.com/buildkite/pipeline-schema/main/schema.json
+---
+
+agents:
+  queue: "android"
+
+steps:
+  - label: "dependency cache"
+    command: |
+      echo "--- 💾 Caching"
+      .buildkite/commands/cache-dependencies.sh
+    plugins: [$CI_TOOLKIT]