release: Publish vendored code

Currently we're not publishing the vendored code as part of the release,
which leads to all the downstream which do not have access to internet
whilst building their components to do this process manually.

Let's be nice to the downstreams, let's publish the vendors ourselves.

Signed-off-by: Fabiano Fidêncio <[email protected]>

.github/workflows/vendor_release.yml

@@ -0,0 +1,24 @@
+name: Generate vendored content for the release
+
+on:
+  release:
+    types: [published]
+
+jobs:
+  generate-and-publish-vendored-code:
+    runs-on: ubuntu-latest
+    steps:
+      - name: Checkout
+        uses: actions/checkout@v4
+
+      - name: Generate and publish cargo vendored tarball
+        run: |
+          tag=$(echo $GITHUB_REF | sed 's|refs/tags/||')
+          tarball_name="guest-components-${tag}-vendor.tar.gz"
+          mkdir -p .cargo
+          cargo vendor --locked >> .cargo/config.toml
+
+          tar -cvzf ${tarball_name} vendor .cargo/config.toml 
+          gh release upload ${tag} ${tarball_name}
+        env:
+          GH_TOKEN: ${{ github.token }}