fix: add workflow_dispatch trigger to crates publish workflow (#313)

The release:published event doesn't fire when GitHub releases are created
by other actions (using GITHUB_TOKEN), which prevents automatic crates.io
publishing. Adding workflow_dispatch allows manual triggering as a fallback.

Author: joshrotenberg

.github/workflows/publish-crates.yml

@@ -3,6 +3,7 @@ name: Publish to crates.io
 on:
   release:
     types: [published]
+  workflow_dispatch:
 
 env:
   CARGO_TERM_COLOR: always