Update Rust crate slab to 0.4.9 (#27480)

This PR contains the following updates:

| Package | Type | Update | Change |
|---|---|---|---|
| [slab](https://togithub.com/tokio-rs/slab) | workspace.dependencies | patch | `0.4.8` -> `0.4.9` |

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GitOrigin-RevId: 459d1cb41bee7528751b6d632e568c6d0bd19877

Cargo.toml

@@ -112,7 +112,7 @@ serde = { version = "1", features = [ "derive" ] }
 serde_json = { version = "1", features = [ "float_roundtrip", "preserve_order" ] }
 sha1 = { version = "0.10.5", features = [ "oid" ] }
 sha2 = { version = "0.10.8" }
-slab = "0.4.8"
+slab = "0.4.9"
 sodiumoxide = "^0.2"
 sourcemap = "8"
 strum = { version = "0.26", features = [ "derive" ] }