Bump serde from 1.0.98 to 1.0.99 (#5540)

Bumps [serde](https://github.com/serde-rs/serde) from 1.0.98 to 1.0.99.
- [Release notes](https://github.com/serde-rs/serde/releases)
- [Commits](https://github.com/serde-rs/serde/compare/v1.0.98...v1.0.99)

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

runtime/Cargo.toml

@@ -22,7 +22,7 @@ maplit = "1.0.1"
 memmap = "0.6.2"
 rand = "0.6.5"
 rayon = "1.1.0"
-serde = { version = "1.0.98", features = ["rc"] }
+serde = { version = "1.0.99", features = ["rc"] }
 serde_derive = "1.0.98"
 serde_json = "1.0.40"
 solana-logger = { path = "../logger", version = "0.18.0-pre1" }