[FLINK-27075][ci] Adds configuration for nightly workflow runs

.github/workflows/flink-nightly-most-recent-released-version.yml

@@ -0,0 +1,62 @@
+# 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.
+
+# The nightly run workflow runs on the most-recently created release branch
+# A separate workflow configuration was necessary (in contrast to using GitHub's
+# matrix strategy) because three layers of composite workflows are not well visualized
+# in GitHub Action.
+
+name: "Nightly (most-recent release)"
+
+on:
+  schedule:
+    - cron: '0 17 * * *'
+  workflow_dispatch:
+
+permissions: read-all
+
+jobs:
+  determine-branch:
+    name: "Select most-recent release branch"
+    runs-on: "ubuntu-latest"
+    outputs:
+      branch: ${{ steps.branch-selection.outputs.branch }}
+    steps:
+      - name: "Flink Checkout"
+        uses: actions/checkout@v3
+        with:
+          persist-credentials: false
+      - name: "Select most-recent release branch"
+        id: branch-selection
+        run: |
+          # actions/checkout only fetches one branch but we need all the branch information from origin
+          git fetch --no-tags --depth=1 origin
+          
+          # filters the release branches and sorts by version
+          selected_branch="$(git branch --remotes | grep -o "release-[0-9]\{1,\}\.[0-9]\{1,\}" | sort -u -t'.' -k2,2V | tail -1)"
+          echo "Most-recently created release branch: ${selected_branch}"
+          echo "branch=${selected_branch}" >> "$GITHUB_OUTPUT"
+
+  nightly:
+    name: "Nightly ${{ needs.determine-branch.outputs.branch }}"
+    needs: determine-branch
+    uses: ./.github/workflows/flink-ci-extended.yml
+    with:
+      branch: ${{ needs.determine-branch.outputs.branch }}
+      supported-jdk-versions: "11 17"
+    secrets:
+      s3_bucket: ${{ secrets.IT_CASE_S3_BUCKET }}
+      s3_access_key: ${{ secrets.IT_CASE_S3_ACCESS_KEY }}
+      s3_secret_key: ${{ secrets.IT_CASE_S3_SECRET_KEY }}