Ruby: Add change-note.

Author: michaelnebel

ruby/ql/src/change-notes/2025-06-17-tagging.md

@@ -0,0 +1,5 @@
+---
+category: queryMetadata
+---
+* Update query metadata tags for `rb/database-query-in-loop` and `rb/useless-assignment-to-local` to align with the established
+[Query file metadata and alert message style guide](https://github.com/github/codeql/blob/main/docs/query-metadata-style-guide.md#quality-query-sub-category-tags).