fix: upgrade @umbraco-cms/backoffice from 15.2.0 to 15.2.1

Snyk has created this PR to upgrade @umbraco-cms/backoffice from 15.2.0 to 15.2.1.

See this package in npm:
@umbraco-cms/backoffice

See this project in Snyk:
https://app.snyk.io/org/jcdcdev/project/3d9804d5-b21c-49c2-9d46-c76f52c51ac0?utm_source=github&utm_medium=referral&page=upgrade-pr

Author: snyk-bot

src/jcdcdev.Umbraco.ReadingTime.Client/package-lock.json

@@ -14,7 +14,7 @@
 	},
 	"devDependencies": {
 		"@hey-api/openapi-ts": "^0.63.2",
-		"@umbraco-cms/backoffice": "^15.2.0",
+		"@umbraco-cms/backoffice": "^15.2.1",
 		"typescript": "^5.7.3",
 		"vite": "^5.4.14"
 	},