CD: Add manual release workflow

This commit implements a naive manual "Publish Release" workflow,
which just creates a GH release with "Package Control.sublime-package" attached.

Required release steps:

1. update version files
   - package_control/__init__.py
   - package-metadata.json
2. commit as "Bump Version"
3. push to remote
4. run "Publish Release" workflow on GH

The first and only goal is to provide a common public method to do a release,
using trustworthy upstream infrastructure.

Ideas for future changes:

1. trigger when creating semver compliant tags.
2. update version files in repo automatically.
3. auto-create the "Bump Version" commit.
4. maybe auto-sign created package
5. auto-upload to packagecontrol.io/...

Author: deathaxe

.github/workflows/publish-release.yml

@@ -0,0 +1,21 @@
+name: Publish Release
+
+on:
+  workflow_dispatch:
+
+jobs:
+  release:
+    name: Create and publish release
+    env:
+      GH_TOKEN: ${{ github.token }}
+    permissions:
+      contents: write
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/checkout@v6
+      - uses: astral-sh/setup-uv@v7
+      - run: |
+          version=$(uv run --quiet python -c "from package_control import __version__;print(__version__)")
+          archive="Package Control.sublime-package"
+          git archive --format zip -o "$archive" master
+          gh release create --generate-notes --latest --target master -t "v$version" "$version" "$archive#$archive"