fix(publish): git tags for private packages (#152)

* fix(publish): git tags for private packages

* tag packages immediately after publish

* prevent spurious tags without release

* add an integration test

* tag private packages in mixed workspaces

* format

* format

Author: goulvenclech

.sampo/changesets/venerable-bard-kullervo.md

@@ -0,0 +1,7 @@
+---
+cargo/sampo: patch
+cargo/sampo-core: patch
+cargo/sampo-github-action: patch
+---
+
+Private packages now receive git version tags during `sampo publish`, ensuring the GitHub Action's published output correctly triggers subsequent workflow steps, even for projects that don't publish to package registries.