Bump serde from 1.0.204 to 1.0.209

Bumps [serde](https://github.com/serde-rs/serde) from 1.0.204 to 1.0.209.
- [Release notes](https://github.com/serde-rs/serde/releases)
- [Commits](serde-rs/serde@v1.0.204...v1.0.209)

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

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

filegram/Cargo.toml

@@ -11,7 +11,7 @@ block-padding = { version = "0.3.3", features = ["std"] }
 chacha20poly1305 = { version = "0.10.1", features = ["std"] }
 image = { version = "0.25.2", features = ["png"], default-features = false }
 imageproc = { version = "0.25.0", default-features = false }
-serde = { version = "1.0.204", features = [
+serde = { version = "1.0.209", features = [
     "std",
     "serde_derive",
 ], default-features = false }