Automate maintenance branch creation [DI-669] (#1372)

- creates `z` branch if major/minor release, based on release branch
with updated (dynamically calculated) version
- creates milestone

Testing (in my fork):
- [example
execution](https://github.com/JackPGreen/hazelcast-cpp-client/actions/runs/19483707385)
- [branch
created](https://github.com/JackPGreen/hazelcast-cpp-client/tree/5.6.z)
- [version update PR
raised](JackPGreen#15)
- [milestone
created](https://github.com/JackPGreen/hazelcast-cpp-client/milestone/3)

Fixes: #1371,
[DI-669](https://hazelcast.atlassian.net/browse/DI-669)

[DI-669]:
https://hazelcast.atlassian.net/browse/DI-669?atlOrigin=eyJpIjoiNWRkNTljNzYxNjVmNDY3MDlhMDU5Y2ZhYzA5YTRkZjUiLCJwIjoiZ2l0aHViLWNvbS1KU1cifQ

Author: JackPGreen

.github/actions/update-project-version/action.yml

@@ -0,0 +1,35 @@
+name: Update project version
+
+inputs:
+  NEXT_VERSION:
+    required: true
+
+runs:
+  using: composite
+  steps:
+    - name: Update `vcpkg.json`
+      shell: bash
+      run: |
+        cat <<< $(jq --arg ver "${{ inputs.NEXT_VERSION }}" '.version = $ver' vcpkg.json) > vcpkg.json
+
+    - name: Update `CMakeLists.txt`s
+      shell: bash
+      run: |
+        find . -name 'CMakeLists.txt' | \
+            xargs perl -0777 -i -pe 's/(project\s*\([^)]*?\bVERSION\s+)\S+/\1$ENV{NEXT_VERSION}/s'
+      env:
+        NEXT_VERSION: ${{ inputs.NEXT_VERSION }}
+
+    - name: Get current branch name
+      id: get-current-branch-name
+      shell: bash
+      run: |
+        echo "name=$(git rev-parse --abbrev-ref HEAD)" >> ${GITHUB_OUTPUT}
+
+    - name: Create Pull Request
+      # https://github.com/peter-evans/create-pull-request/releases/tag/v7.0.8
+      uses: peter-evans/create-pull-request@271a8d0340265f705b14b6d32b9829c1cb33d45e
+      with:
+        branch: Update_version_to_${{ inputs.NEXT_VERSION }}_run_${{ github.run_id }}
+        title: Update version to `${{ inputs.NEXT_VERSION }}` in `${{ steps.get-current-branch-name.outputs.name }}`
+        body: ""

.github/workflows/create-release-branch.yml

@@ -29,28 +29,45 @@ jobs:
           git checkout -b ${{ steps.project_version.outputs.version }}
           git push origin ${{ steps.project_version.outputs.version }}
 
+      # https://github.com/madhead/semver-utils/releases/tag/v4.3.0
+      - uses: madhead/semver-utils@36d1e0ed361bd7b4b77665de8093092eaeabe6ba
+        id: parse-version
+        with:
+          version: ${{ steps.project_version.outputs.version }}
+
+      - name: Compute Z-Branch name
+        if: steps.parse-version.outputs.patch == '0'
+        id: compute-z-branch-name
+        run: |
+          echo "name=${{ steps.parse-version.outputs.major }}.${{ steps.parse-version.outputs.minor }}.z" >> ${GITHUB_OUTPUT}
+
+      - name: Create `${{ steps.compute-z-branch-name.outputs.name }}` branch
+        if: steps.parse-version.outputs.patch == '0'
+        run: |
+          git checkout -b ${{ steps.compute-z-branch-name.outputs.name }}
+          git push origin ${{ steps.compute-z-branch-name.outputs.name }}
+
+      - if: steps.parse-version.outputs.patch == '0'
+        uses: hazelcast/hazelcast-cpp-client/.github/actions/update-project-version@master
+        with:
+          NEXT_VERSION: ${{ steps.parse-version.outputs.inc-patch }}
+
   update-version:
     name: Update next version in `${{ inputs.BRANCH_NAME }}` to `${{ inputs.NEXT_VERSION }}`
     runs-on: ubuntu-latest
-    env:
-        NEW_VERSION: ${{ inputs.NEXT_VERSION }}
     steps:
       - uses: actions/checkout@v5
         with:
           ref: ${{ inputs.BRANCH_NAME }}
 
-      - name: Update `vcpkg.json`
-        run: |
-            cat <<< $(jq --arg ver "${NEW_VERSION}" '.version = $ver' vcpkg.json) > vcpkg.json
+      - uses: hazelcast/hazelcast-cpp-client/.github/actions/update-project-version@master
+        with:
+          NEXT_VERSION: ${{ inputs.NEXT_VERSION }}
 
-      - name: Update `CMakeLists.txt`s
+      - name: Create milestone
         run: |
-            find . -name 'CMakeLists.txt' | \
-                xargs perl -0777 -i -pe 's/(project\s*\([^)]*?\bVERSION\s+)\S+/\1$ENV{NEW_VERSION}/s'
-
-      - name: Create Pull Request
-        uses: peter-evans/create-pull-request@v7
-        with:
-          branch: Update_version_to_${{ inputs.NEXT_VERSION }}_run_${{ github.run_id }}
-          title: Update development version to `${{ inputs.NEXT_VERSION }}`
-          body: ""
+            gh api \
+              /repos/${GITHUB_REPOSITORY}/milestones \
+              --field title='${{ inputs.NEXT_VERSION }}'
+        env:
+            GH_TOKEN: ${{ github.token }}

.github/workflows/release.yml

@@ -79,7 +79,8 @@ jobs:
             "${GH_PAGES_BRANCH}/api-index.html"
 
       - name: Create Pull Request
-        uses: peter-evans/create-pull-request@v7
+        # https://github.com/peter-evans/create-pull-request/releases/tag/v7.0.8
+        uses: peter-evans/create-pull-request@271a8d0340265f705b14b6d32b9829c1cb33d45e
         with:
           branch: ${{ needs.prepare.outputs.tag_name }}_doc_update_run_${{ github.run_id }}
           title: Add the new C++ client release (`${{ needs.prepare.outputs.tag_name }}`) documentation