Bump serde from 1.0.180 to 1.0.188

Bumps [serde](https://github.com/serde-rs/serde) from 1.0.180 to 1.0.188.
- [Release notes](https://github.com/serde-rs/serde/releases)
- [Commits](serde-rs/serde@v1.0.180...v1.0.188)

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

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

Cargo.toml

@@ -9,7 +9,7 @@ repository = "https://github.com/yammmt/last-date.git"
 
 [dependencies]
 rocket = "0.5.0-rc.3"
-serde = "1.0.180"
+serde = "1.0.188"
 serde_json = "^1.0"
 serde_derive = "1.0.126"
 diesel = { version = "^2.1", features = ["sqlite", "r2d2", "chrono"] }