fix(deps): update rust crate tch to 0.20.0

Author: renovate[bot]

Cargo.toml

@@ -8,7 +8,7 @@ name = "pancakellm"
 path = "src/lib.rs"
 
 [dependencies]
-tch = "0.17.0"
+tch = "0.20.0"
 tokenizers = "0.20.0"
 serde = { version = "1.0", features = ["derive"] }
 serde_json = "1.0"