Update Rust crate speedy to 0.8.7

Author: renovate[bot]

internal/state/Cargo.toml

@@ -10,7 +10,7 @@ derive_more = "0.99.17"
 git-fast-import = { path = "../../git-fast-import" }
 log = "0.4.14"
 serde = { version = "1.0.136", features = ["derive", "rc"] }
-speedy = "0.8.1"
+speedy = "0.8.7"
 thiserror = "1.0.30"
 tokio = { version = "1.16.1", features = ["io-util", "sync"] }
 zstd = "0.10.0"