feat(ci): automatically add release version to Pongo

When a tag is created, this workflow would automatically
create a PR on 'kong/kong-pongo' to add that version.

.github/workflows/add_new_release_to_pongo.yml

@@ -0,0 +1,125 @@
+name: Add New Release to Pongo
+
+on:
+  push:
+    tags:
+    - '[1-9]+.[0-9]+.[0-9]+'
+
+jobs:
+  set_vars:
+    name: Set Vars
+    runs-on: ubuntu-latest
+    outputs:
+      ce_ee: ${{ steps.define_vars.outputs.CE_EE }}
+      tag_version: ${{ steps.define_vars.outputs.TAG_VERSION }}
+      pr_branch: ${{ steps.define_vars.outputs.PR_BRANCH }}
+    steps:
+    - name: Define Vars
+      id: define_vars
+      shell: bash
+      run: |
+        if [[ "${GITHUB_REPOSITORY}" = "kong/kong" ]] ; then
+          CE_EE=CE
+        elif [[ "${GITHUB_REPOSITORY}" = "kong/kong-ee" ]] ; then
+          CE_EE=EE
+        fi
+        echo "CE_EE=$CE_EE" >> "$GITHUB_OUTPUT"
+
+        if [[ "${{ github.event_name }}" == "push" ]] ; then
+          TAG_VERSION="${{ github.ref_name }}"
+        elif [[ "${{ github.event_name }}" == "release" ]] ; then
+          TAG_VERSION="${{ github.event.release.tag_name }}"
+        fi
+        echo "TAG_VERSION=$TAG_VERSION" >> "$GITHUB_OUTPUT"
+
+        echo "PR_BRANCH=add-${CE_EE,,}-version-${TAG_VERSION}" >> "$GITHUB_OUTPUT"
+  add_release_to_pongo:
+    name: Add Release to Pongo
+    runs-on: ubuntu-latest
+    needs:
+    - set_vars
+    env:
+      GITHUB_TOKEN: ${{ secrets.PAT }}
+    steps:
+    - name: Checkout Pongo
+      id: checkout_pongo
+      uses: actions/checkout@v4
+      with:
+        token: ${{ secrets.PAT }}
+        repository: kong/kong-pongo
+        ref: master
+    - name: Update Versions File
+      id: update_versions_file
+      shell: bash
+      run: |
+        git config --global user.email "[email protected]"
+        git config --global user.name "GHA Bot"
+
+        git checkout -b "${{ needs.set_vars.outputs.pr_branch }}"
+
+        ce_ee="${{ needs.set_vars.outputs.ce_ee }}"
+        VERSIONS_FILE="assets/kong_${ce_ee}_versions.ver"
+        if [[ ! -f $VERSIONS_FILE ]]; then
+          echo "Versions file '$VERSIONS_FILE' not found"
+          exit 1
+        fi
+
+        tag_version="${{ needs.set_vars.outputs.tag_version }}"
+        echo "${tag_version}" >> "$VERSIONS_FILE"
+        sort --version-sort -o "$VERSIONS_FILE" "$VERSIONS_FILE"
+        git add "$VERSIONS_FILE"
+        git commit -m "feat(version): add Kong ${ce_ee} version $tag_version"
+    - name: Checkout Kong ${{ needs.set_vars.outputs.ce_ee }}
+      id: checkout_kong
+      uses: actions/checkout@v4
+      with:
+        token: ${{ secrets.PAT }}
+        ref: ${{ needs.set_vars.outputs.tag_version }}
+        path: ${{ github.event.repository.name }}
+    - name: Update Artifacts
+      id: update_artifacts
+      shell: bash
+      run: |
+        repo_name=${{ github.event.repository.name }}
+        tag_version="${{ needs.set_vars.outputs.tag_version }}"
+
+        mkdir -p "kong-versions/${tag_version}/kong"
+        cp    "${repo_name}/Makefile" "kong-versions/${tag_version}/kong/"
+        cp -R "${repo_name}/bin"      "kong-versions/${tag_version}/kong/"
+
+        mkdir -p "kong-versions/${tag_version}/kong/spec"
+        for fname in ${repo_name}/spec/* ; do
+          case $fname in
+            (${repo_name}/spec/[0-9]*)
+              # skip test files
+              ;;
+            (*)
+              cp -R "$fname" "kong-versions/${tag_version}/kong/spec/"
+              ;;
+          esac
+        done
+
+        if [[ -d "${repo_name}/spec-ee" ]] ; then
+          mkdir -p "kong-versions/${tag_version}/kong/spec-ee"
+          for fname in ${repo_name}/spec-ee/* ; do
+            case $fname in
+              (${repo_name}/spec-ee/[0-9]*)
+                # skip test files
+                ;;
+              (*)
+                cp -R "$fname" "kong-versions/${tag_version}/kong/spec-ee/"
+                ;;
+            esac
+          done
+        fi
+
+        rm -rf "${repo_name}"
+
+        git add kong-versions/
+        git commit -m "chore(version): add Kong "${{ needs.set_vars.outputs.ce_ee }}" version $tag_version artifacts"
+    - name: Create PR
+      id: create_pr
+      shell: bash
+      run: |
+        git push -u origin ${{ needs.set_vars.outputs.pr_branch }}
+        gh pr create -B master -H "${{ needs.set_vars.outputs.pr_branch }}" --title "Add Kong "${{ needs.set_vars.outputs.ce_ee }}" version ${{ needs.set_vars.outputs.tag_version }}" --body 'Created by GHA Bot.'