Update proc-macro-warning (#13876)

* Update proc-macro-warning

Closes https://github.com/paritytech/substrate/issues/13872

Signed-off-by: Oliver Tale-Yazdi <oliver.tale-yazdi@parity.io>

* Update to v0.3.1 (including syn 2.0)

Signed-off-by: Oliver Tale-Yazdi <oliver.tale-yazdi@parity.io>

* Revert "Update to v0.3.1 (including syn 2.0)"

CI is red since it Polkadot uses a different syn version…
Going to update it lean.

This reverts commit 3240d379b72f6f722eaf502ed49e9a1b0f79db4b.

Signed-off-by: Oliver Tale-Yazdi <oliver.tale-yazdi@parity.io>

---------

Signed-off-by: Oliver Tale-Yazdi <oliver.tale-yazdi@parity.io>

substrate/Cargo.lock

@@ -7552,9 +7552,9 @@ dependencies = [
 
 [[package]]
 name = "proc-macro-warning"
-version = "0.2.0"
+version = "0.3.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "9d4f284d87b9cedc2ff57223cbc4e3937cd6063c01e92c8e2a8c080df0013933"
+checksum = "f0e25495609acefcaeb5052edad8ac91017c9bc98fc38ef321ed524e50b68bac"
 dependencies = [
  "proc-macro2",
  "quote",

substrate/frame/support/procedural/Cargo.toml

@@ -23,7 +23,7 @@ proc-macro2 = "1.0.56"
 quote = "1.0.26"
 syn = { version = "2.0.14", features = ["full"] }
 frame-support-procedural-tools = { version = "4.0.0-dev", path = "./tools" }
-proc-macro-warning = { version = "0.2.0", default-features = false }
+proc-macro-warning = { version = "0.3.0", default-features = false }
 
 [features]
 default = ["std"]