fix(ci): dispatch GoReleaser after release-please; allow Tests dispatch (#13)

GITHUB_TOKEN cannot trigger push:tags workflows, so Release never ran
after release-please. Dispatch release.yml explicitly when a release is
created. Add workflow_dispatch to Tests for on-demand main verification.

.github/workflows/test.yml

@@ -4,6 +4,7 @@ on:
   push:
     branches: [main]
   pull_request:
+  workflow_dispatch:
 
 permissions:
   contents: read