[build] Various build workflow improvements

- Wait for build before publishing to PyPI
- Do not run `meta_files` job if release is cancelled
- Customizable channel in release workflow
- Display badges above changelog

Authored by: bashonly, Grub4K

.github/workflows/release-nightly.yml

@@ -46,6 +46,7 @@ jobs:
     permissions:
       contents: write
     with:
-      nightly: true
+      channel: nightly
+      prerelease: true
       version: ${{ needs.prepare.outputs.version }}
       target_commitish: ${{ github.sha }}