ci: configure dependabot to monitor actions/* dependencies

Part of #1590

[skip ci]

Author: php-coder

.github/dependabot.yml

@@ -26,3 +26,24 @@ updates:
     labels: [ "kind/dependency-update" ]
     # https://docs.github.com/en/code-security/dependabot/dependabot-version-updates/configuration-options-for-the-dependabot.yml-file#open-pull-requests-limit
     open-pull-requests-limit: 1
+
+  - package-ecosystem: "github-actions"
+    directory: "/"
+    # https://docs.github.com/en/code-security/dependabot/dependabot-version-updates/configuration-options-for-the-dependabot.yml-file#allow
+    allow:
+      - dependency-name: "actions/checkout"
+      - dependency-name: "actions/setup-java"
+      - dependency-name: "actions/upload-artifact"
+    # https://docs.github.com/en/code-security/dependabot/dependabot-version-updates/configuration-options-for-the-dependabot.yml-file#scheduleinterval
+    schedule:
+      interval: "daily"
+      time: "08:00"
+      timezone: "Asia/Novosibirsk"
+    # https://docs.github.com/en/code-security/dependabot/dependabot-version-updates/configuration-options-for-the-dependabot.yml-file#commit-message
+    commit-message:
+      prefix: "ci"
+    assignees: [ "php-coder" ]
+    reviewers: [ "php-coder" ]
+    labels: [ "kind/dependency-update", "area/ci" ]
+    # https://docs.github.com/en/code-security/dependabot/dependabot-version-updates/configuration-options-for-the-dependabot.yml-file#open-pull-requests-limit
+    open-pull-requests-limit: 1