Bump backbone from 1.6.0 to 1.6.1 in the external-miscellaneous group

---
updated-dependencies:
- dependency-name: backbone
  dependency-version: 1.6.1
  dependency-type: direct:production
  update-type: version-update:semver-patch
  dependency-group: external-miscellaneous
...

Signed-off-by: dependabot[bot] <support@github.com>

Author: dependabot[bot]

package-lock.json

@@ -144,7 +144,7 @@
 		"@wordpress/warning": "3.19.1",
 		"@wordpress/widgets": "4.19.4",
 		"@wordpress/wordcount": "4.19.1",
-		"backbone": "1.6.0",
+		"backbone": "1.6.1",
 		"clipboard": "2.0.11",
 		"core-js-url-browser": "3.6.4",
 		"element-closest": "3.0.2",