ci(release-drafter): escape @ and # in PR-title release notes

PR titles that mention a decorator (e.g. `@schema`) or an issue (e.g.
`feat(#1425):`) were rendering as live GitHub mentions/links in the drafted
release notes — the `@schema` in #1467's title showed up as a spurious
"Schema" contributor on the v2.3.0 draft. Add @ and # to change-title-escapes
(the config comment already documents this) so title text stays literal while
the template's real $AUTHOR credit and (#PR) link are unaffected.

Author: dimitri-yatsenko

.github/release_drafter.yaml

@@ -28,7 +28,7 @@ categories:
   - title: '📝 Documentation'
     label: 'documentation'
 change-template: '- $TITLE(#$NUMBER)@$AUTHOR'
-change-title-escapes: '\<*_&' # You can add # and @ to disable mentions, and add ` to disable code blocks.
+change-title-escapes: '\<*_&@#' # escape @ and # so decorator/issue refs in PR titles (e.g. `@schema`) don't render as spurious mentions/links in release notes.
 template: |
   $CHANGES