CI: stricter matching on tag names for release builds

Author: cknitt

.github/workflows/ci.yml

@@ -3,7 +3,11 @@ name: CI
 on:
   push:
     branches: [master]
-    tags: ["v*"]
+    # See https://docs.github.com/en/actions/using-workflows/workflow-syntax-for-github-actions#filter-pattern-cheat-sheet
+    tags:
+      - "v[0-9].[0-9].[0-9]"
+      - "v[0-9].[0-9].[0-9]-*"
+
   pull_request:
     branches: [master]