[CI] Enable Dependabot for GitHub Actions

[kou]

Describe the enhancement requested

We can update GitHub Actions (semi) automatically by enabling Dependabot.

For example, we can enable Dependabot for GitHub Actions by adding .github/dependabot.yml:

diff --git a/.github/dependabot.yml b/.github/dependabot.yml
new file mode 100644
index 000000000..76f39ea3d
--- /dev/null
+++ b/.github/dependabot.yml
@@ -0,0 +1,23 @@
+# Licensed to the Apache Software Foundation (ASF) under one
+# or more contributor license agreements.  See the NOTICE file
+# distributed with this work for additional information
+# regarding copyright ownership.  The ASF licenses this file
+# to you under the Apache License, Version 2.0 (the
+# "License"); you may not use this file except in compliance
+# with the License.  You may obtain a copy of the License at
+#
+#   http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing,
+# software distributed under the License is distributed on an
+# "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
+# KIND, either express or implied.  See the License for the
+# specific language governing permissions and limitations
+# under the License.
+
+version: 2
+updates:
+  - package-ecosystem: "github-actions"
+    directory: "/"
+    schedule:
+      interval: "daily"

See also: https://docs.github.com/en/code-security/dependabot/working-with-dependabot/keeping-your-actions-up-to-date-with-dependabot

Component(s)

Continuous Integration

[kou]

We may want to configure the commit message by Dependabot to adjust our style. For example, we may want to use MINOR: [CI] prefix.
See also: https://docs.github.com/en/code-security/dependabot/dependabot-version-updates/configuration-options-for-the-dependabot.yml-file#commit-message

[westonpace]

So this is just for upgrading our github actions? +1 to this idea.

[kou]

Yes!