CLI: remove top-level Cargo workspace, bump deps, raise dist version (#…

…1628)

This is some general maintenance around the CLI.

Removing the top-level Cargo.toml helps with rust-analyzer
configuration. Initially it wasn't clear if dist required this
(bootstrapping the dist workspace didn't seem to work without it) but
now that everything is in place, I think we don't need it.

Since there's no longer a top-level `Cargo.lock` I took this opportunity
to `cargo update` the CLI's package-local lockfile.


---

I verified the build workflows are all still happy with this change by
setting `pr-run-mode = "upload"` in `dist-workspace.toml`.


https://github.com/svix/svix-webhooks/actions/runs/12677571884/job/35333195678?pr=1628

.github/workflows/release.yml

@@ -67,7 +67,7 @@ jobs:
         # we specify bash to get pipefail; it guards against the `curl` command
         # failing. otherwise `sh` won't catch that `curl` returned non-0
         shell: bash
-        run: "curl --proto '=https' --tlsv1.2 -LsSf https://github.com/axodotdev/cargo-dist/releases/download/v0.27.0/cargo-dist-installer.sh | sh"
+        run: "curl --proto '=https' --tlsv1.2 -LsSf https://github.com/axodotdev/cargo-dist/releases/download/v0.28.0/cargo-dist-installer.sh | sh"
       - name: Cache dist
         uses: actions/upload-artifact@v4
         with: