feat: Add Changelog build workflow

.github/workflows/changelog-build.yml

@@ -0,0 +1,118 @@
+name: 'Changelog Build (Release)'
+
+on:
+  workflow_dispatch:
+    inputs:
+      last-release-tag:
+        description: Last Git tag to start from (exclusive) (e.g. `v2.0.0`)
+        type: string
+        required: true
+      release-branch:
+        description: Release branch to build changelog on (e.g. `r2.1.0`)
+        type: string
+        required: true
+      changelog-main-content:
+        description: Custom changelog content to include before detailed changelogs
+        type: string
+        required: false
+        default: ''
+
+jobs:
+  changelog:
+    runs-on: ubuntu-latest
+    steps:
+      - name: Checkout branch
+        uses: actions/checkout@v4
+        with:
+          ref: main
+          fetch-depth: 0
+
+      - name: Build Changelog
+        id: github_tag
+        uses: mikepenz/[email protected]
+        env:
+          GITHUB_TOKEN: ${{ secrets.GITHUB_TOKEN }}
+        with:
+          owner: ${{ github.repository_owner }}
+          repo: ${{ github.event.repository.name }}
+          ignorePreReleases: "false"
+          failOnError: "false"
+          fromTag: ${{ inputs.last-release-tag }}
+          toTag: ${{ inputs.release-branch }}
+
+      - name: Update changelog file
+        env: 
+          RELEASE_BRANCH: ${{ inputs.release-branch }}
+          CHANGELOG: ${{ steps.github_tag.outputs.changelog }}
+          MAIN_CONTENT: ${{ inputs.changelog-main-content }}
+        shell: bash -x -e -u -o pipefail {0}
+        run: |
+          RELEASE_VERSION=${RELEASE_BRANCH#r}
+          CHANGELOG=$(echo "$CHANGELOG" | sed '/^[[:blank:]]*#/s/#/###/')
+
+          # Build release notes starting with version header
+          RELEASE_NOTES="## NVIDIA DFM $RELEASE_VERSION"
+
+          # Add custom content if provided
+          if [ -n "$MAIN_CONTENT" ]; then
+            RELEASE_NOTES="$RELEASE_NOTES
+
+          $MAIN_CONTENT"
+          fi
+
+          # Add detailed changelogs section
+          RELEASE_NOTES="$RELEASE_NOTES
+
+          ### Detailed Changelogs:
+
+          $CHANGELOG"
+
+          printf "%s\n" "$RELEASE_NOTES" | sed '/<!-- Next changelog -->/r /dev/stdin' CHANGELOG.md > CHANGELOG.tmp.md
+
+          mv CHANGELOG.tmp.md CHANGELOG.md
+
+      - name: Inspect new changelog file
+        run: cat CHANGELOG.md
+
+      - name: Create or update label
+        uses: actions/github-script@v6
+        with:
+          script: |
+            const labelName = '${{ inputs.release-branch }}';
+            const labelColor = '0366d6'; // Blue color
+            const labelDescription = `Release ${labelName}`;
+
+            try {
+              // Try to get the label
+              await github.rest.issues.getLabel({
+                owner: context.repo.owner,
+                repo: context.repo.repo,
+                name: labelName
+              });
+              console.log(`Label '${labelName}' already exists`);
+            } catch (error) {
+              if (error.status === 404) {
+                // Label doesn't exist, create it
+                await github.rest.issues.createLabel({
+                  owner: context.repo.owner,
+                  repo: context.repo.repo,
+                  name: labelName,
+                  color: labelColor,
+                  description: labelDescription
+                });
+                console.log(`Created label '${labelName}'`);
+              } else {
+                throw error;
+              }
+            }
+
+      - name: Create Pull Request
+        uses: peter-evans/create-pull-request@v7
+        with:
+          commit-message: "beep boop: Update changelog"
+          title: "Update changelog for `${{ inputs.release-branch }}`"
+          signoff: true
+          sign-commits: true
+          base: main
+          branch: bot/chore/update-changelog-into-${{ inputs.release-branch }}
+          labels: ${{ inputs.release-branch }}