CI: all-in-one workflow

This change moves all CI jobs into a single workflow. A single workflow comes with a couple advantages:
* all jobs are visible on one page
* option to re-run all failed jobs at once

The refactoring also simplifies the `.asf.yaml` file by referencing a single required check that can only succeeds if dependent jobs were successful.

The actual CI jobs are in the `ci.yml` file, which is only triggered via a `workflow_call` event.
There are two workflows that call `ci.yml`:
* `ci-main.yml` for `main` and `release/*` branches, with a concurrency group that does not cancel already running workflows
* `ci-pr.yml` for PRs with a concurrency group that cancels previous CI runs

The names of these two calling workflows include information that enrich the workflow view, and the workflows for main, release branches and PRs are grouped separartely in the GH Actions page for the repository. In other words, the reference name (for main + release branches) or the PR number and title are shown in the workflow runs list on the GH Actions page.

Author: snazy

.asf.yaml

@@ -47,6 +47,14 @@ github:
 
       required_linear_history: true
 
+      required_status_checks:
+        # strict means "Require branches to be up to date before merging".
+        strict: false
+        # Contexts are the names of checks that must pass. This is the value
+        # of the job's `name` property if it's present.
+        contexts:
+          - "Required Checks"
+
   features:
     wiki: false
     issues: true

.github/workflows/check-md-link.yml

@@ -0,0 +1,34 @@
+#
+# 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.
+#
+
+name: CI/main
+run-name: CI/${{github.ref_name}}
+
+on:
+  push:
+    branches: [ "main", "release/*" ]
+
+concurrency:
+  group: ${{ github.workflow }}-${{ github.ref }}
+  cancel-in-progress: false
+
+jobs:
+  ci-main:
+    name: CI/${{ github.ref_name }}
+    uses: ./.github/workflows/ci.yml

.github/workflows/ci-main.yml

@@ -0,0 +1,34 @@
+#
+# 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.
+#
+
+name: CI/PR
+run-name: PR#${{ github.event.number }} ${{ github.event.pull_request.title }}
+
+on:
+  pull_request:
+    branches: [ "main", "release/*" ]
+
+concurrency:
+  group: ${{ github.workflow }}-${{ github.ref }}
+  cancel-in-progress: true
+
+jobs:
+  ci-pr:
+    name: PR#${{ github.event.number }} ${{ github.event.pull_request.title }}
+    uses: ./.github/workflows/ci.yml