Bump serde from 1.0.218 to 1.0.219

Bumps [serde](https://github.com/serde-rs/serde) from 1.0.218 to 1.0.219.
- [Release notes](https://github.com/serde-rs/serde/releases)
- [Commits](serde-rs/serde@v1.0.218...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>

Author: dependabot[bot]

Cargo.lock

@@ -21,7 +21,7 @@ path = "src/lib.rs"
 unstable = []
 
 [dependencies]
-serde = { version = "1.0.218", optional = true }
+serde = { version = "1.0.219", optional = true }
 
 [dev-dependencies]
 bencher = "0.1.5"