Patch proc-macro-crate 2 to proc-macro-crate 3

Updates toml_edit to 0.21.

Cargo.toml

@@ -73,6 +73,7 @@ members = [
   "patches/option-ext",
   "patches/directories-next",
   "patches/mach",
+  "patches/proc-macro-crate",
 ]
 
 # Always compile Monero (and a variety of dependencies) with optimizations due
@@ -118,6 +119,9 @@ directories-next = { path = "patches/directories-next" }
 # mach is unmaintained, so this wraps mach2 as mach
 mach = { path = "patches/mach" }
 
+# proc-macro-crate 2 binds to an old version of toml for msrv so we patch to 3
+proc-macro-crate = { path = "patches/proc-macro-crate" }
+
 [workspace.lints.clippy]
 unwrap_or_default = "allow"
 borrow_as_ptr = "deny"

patches/proc-macro-crate/Cargo.toml

@@ -0,0 +1,17 @@
+[package]
+name = "proc-macro-crate"
+version = "2.0.1"
+description = "Patches proc-macro-crate 2 to 3"
+license = "MIT"
+repository = "https://github.com/serai-dex/serai/tree/develop/patches/proc-macro-crate"
+authors = ["Luke Parker <[email protected]>"]
+keywords = []
+edition = "2021"
+rust-version = "1.66"
+
+[package.metadata.docs.rs]
+all-features = true
+rustdoc-args = ["--cfg", "docsrs"]
+
+[dependencies]
+proc-macro-crate = "3"

patches/proc-macro-crate/src/lib.rs

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