Remove unused patch for parking_lot_core

patches/parking_lot_core/Cargo.toml

@@ -1,16 +0,0 @@
-[package]
-name = "parking_lot_core"
-version = "0.8.6"
-description = "parking_lot_core which patches to the latest update"
-license = "MIT"
-repository = "https://github.com/serai-dex/serai/tree/develop/patches/parking_lot_core"
-authors = ["Luke Parker <lukeparker5132@gmail.com>"]
-keywords = []
-edition = "2021"
-
-[package.metadata.docs.rs]
-all-features = true
-rustdoc-args = ["--cfg", "docsrs"]
-
-[dependencies]
-parking_lot_core = "0.9"

patches/parking_lot_core/src/lib.rs

@@ -1 +0,0 @@
-pub use parking_lot_core::*;