chore(deps): update cron requirement from 0.14.0 to 0.15.0

Updates the requirements on [cron](https://github.com/zslayton/cron) to permit the latest version.
- [Release notes](https://github.com/zslayton/cron/releases)
- [Commits](zslayton/cron@v0.14.0...v0.15.0)

---
updated-dependencies:
- dependency-name: cron
  dependency-type: direct:production
...

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

silent/Cargo.toml

@@ -63,7 +63,7 @@ tokio-util = "0.7.13"
 anyhow = "1.0.95"
 
 # Scheduler
-cron = { version = "0.14.0", optional = true }
+cron = { version = "0.15.0", optional = true }
 
 # Multipart
 multer = { version = "3.1.0", optional = true }