Auto merge of #26578 - servo:dependabot/cargo/synstructure-0.12.3, r=jdm

Bump synstructure from 0.12.1 to 0.12.3

Bumps [synstructure](https://github.com/mystor/synstructure) from 0.12.1 to 0.12.3.
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Cargo.lock

@@ -5665,9 +5665,9 @@ dependencies = [
 
 [[package]]
 name = "synstructure"
-version = "0.12.1"
+version = "0.12.3"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "3f085a5855930c0441ca1288cf044ea4aecf4f43a91668abdb870b4ba546a203"
+checksum = "67656ea1dc1b41b1451851562ea232ec2e5a80242139f7e679ceccfb5d61f545"
 dependencies = [
  "proc-macro2 1.0.1",
  "quote 1.0.2",