Move OptimismHardfork to new crate reth_optimism_forks (#10963)

crates/optimism/hardforks/Cargo.toml

@@ -0,0 +1,31 @@
+[package]
+name = "reth-optimism-forks"
+version.workspace = true
+edition.workspace = true
+rust-version.workspace = true
+license.workspace = true
+homepage.workspace = true
+repository.workspace = true
+description = "Optimism hardforks used in op-reth"
+
+[lints]
+workspace = true
+
+[dependencies]
+# reth
+reth-ethereum-forks.workspace = true
+
+# ethereum
+alloy-chains.workspace = true
+alloy-primitives.workspace = true
+
+# io
+serde = { workspace = true, optional = true }
+
+# misc
+once_cell.workspace = true
+
+[features]
+default = ["std"]
+std = []
+serde = ["dep:serde"]