Bump serde from 1.0.215 to 1.0.219 in /backend

Bumps [serde](https://github.com/serde-rs/serde) from 1.0.215 to 1.0.219.
- [Release notes](https://github.com/serde-rs/serde/releases)
- [Commits](https://github.com/serde-rs/serde/compare/v1.0.215...v1.0.219)

---
updated-dependencies:
- dependency-name: serde
  dependency-type: direct:production
  update-type: version-update:semver-patch
...

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

backend/reconcile/Cargo.toml

@@ -7,7 +7,7 @@ license.workspace = true
 repository.workspace = true
 
 [dependencies]
-serde = { version = "1.0.215", optional = true }
+serde = { version = "1.0.219", optional = true }
 
 [features]
 serde = [ "dep:serde" ]