chore: remove backup workflow file from .github/workflows

Backup files in workflows/ add noise and confusion. The file can be
recovered from git history if needed.

.github/workflows/auto-versioning.yml.backup

@@ -1,95 +0,0 @@
-name: Auto Versioning and Release
-
-on:
-  push:
-    branches: [ main ]
-
-concurrency:
-  group: ${{ github.workflow }}-${{ github.ref }}
-  cancel-in-progress: false
-
-permissions:
-  contents: write  # Required for creating releases via API
-
-jobs:
-  version:
-    runs-on: ubuntu-latest
-    steps:
-      - name: Checkout
-        uses: actions/checkout@8e8c483db84b4bee98b60c0593521ed34d9990e8 # v6
-        with:
-          fetch-depth: 0
-
-      - name: Calculate Semantic Version
-        id: semver
-        uses: paulhatch/semantic-version@a8f8f59fd7f0625188492e945240f12d7ad2dca3 # v5.4.0
-        with:
-          # The prefix to use to create tags
-          tag_prefix: "v"
-          # Regex pattern for major version bump (breaking changes)
-          # Matches: "feat!:", "fix!:", "BREAKING CHANGE:" in commit messages
-          major_pattern: "/!:|BREAKING CHANGE:/"
-          # Regex pattern for minor version bump (new features)
-          # Matches: "feat:" prefix in commit messages (Conventional Commits)
-          minor_pattern: "/feat:/"
-          # Pattern to determine formatting
-          version_format: "${major}.${minor}.${patch}"
-          # If no tags are found, this version is used
-          version_from_branch: "0.0.0"
-          # This helps it search through history to find the last tag
-          search_commit_body: true
-          # Important: This enables the output 'changed' which your other steps rely on
-          enable_prerelease_mode: false
-
-      - name: Show version
-        run: |
-          echo "Next version: ${{ steps.semver.outputs.version }}"
-          echo "Version changed: ${{ steps.semver.outputs.changed }}"
-
-      - name: Determine tag name
-        id: determine_tag
-        run: |
-          # Normalize the version: remove any leading 'v' so we don't end up with 'vvX.Y.Z'
-          RAW="${{ steps.semver.outputs.version }}"
-          VERSION_NO_V="${RAW#v}"
-          TAG="v${VERSION_NO_V}"
-          echo "Determined tag: $TAG"
-          echo "tag=$TAG" >> $GITHUB_OUTPUT
-
-      - name: Check for existing GitHub Release
-        id: check_release
-        run: |
-          TAG=${{ steps.determine_tag.outputs.tag }}
-          echo "Checking for release for tag: ${TAG}"
-          STATUS=$(curl -s -o /dev/null -w "%{http_code}" \
-            -H "Authorization: token ${GITHUB_TOKEN}" \
-            -H "Accept: application/vnd.github+json" \
-            "https://api.github.com/repos/${GITHUB_REPOSITORY}/releases/tags/${TAG}") || true
-          if [ "${STATUS}" = "200" ]; then
-            echo "exists=true" >> $GITHUB_OUTPUT
-            echo "ℹ️  Release already exists for tag: ${TAG}"
-          else
-            echo "exists=false" >> $GITHUB_OUTPUT
-            echo "✅ No existing release found for tag: ${TAG}"
-          fi
-        env:
-          GITHUB_TOKEN: ${{ secrets.GITHUB_TOKEN }}
-
-      - name: Create GitHub Release (creates tag via API)
-        if: ${{ steps.semver.outputs.changed == 'true' && steps.check_release.outputs.exists == 'false' }}
-        uses: softprops/action-gh-release@a06a81a03ee405af7f2048a818ed3f03bbf83c7b # v2
-        with:
-          tag_name: ${{ steps.determine_tag.outputs.tag }}
-          name: Release ${{ steps.determine_tag.outputs.tag }}
-          generate_release_notes: true
-          make_latest: true
-          draft: false
-          prerelease: false
-        env:
-          GITHUB_TOKEN: ${{ secrets.GITHUB_TOKEN }}
-
-      - name: Output release information
-        if: ${{ steps.semver.outputs.changed == 'true' && steps.check_release.outputs.exists == 'false' }}
-        run: |
-          echo "✅ Successfully created release: ${{ steps.determine_tag.outputs.tag }}"
-          echo "📦 Release URL: https://github.com/${{ github.repository }}/releases/tag/${{ steps.determine_tag.outputs.tag }}"