build(deps): bump proc-macro2 from 1.0.19 to 1.0.20

Bumps [proc-macro2](https://github.com/alexcrichton/proc-macro2) from 1.0.19 to 1.0.20.
- [Release notes](https://github.com/alexcrichton/proc-macro2/releases)
- [Commits](https://github.com/alexcrichton/proc-macro2/compare/1.0.19...1.0.20)

Signed-off-by: dependabot-preview[bot] <support@dependabot.com>

Cargo.lock

@@ -1202,9 +1202,9 @@ checksum = "eba180dafb9038b050a4c280019bbedf9f2467b61e5d892dcad585bb57aadc5a"
 
 [[package]]
 name = "proc-macro2"
-version = "1.0.19"
+version = "1.0.20"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "04f5f085b5d71e2188cb8271e5da0161ad52c3f227a661a3c135fdf28e258b12"
+checksum = "175c513d55719db99da20232b06cda8bab6b83ec2d04e3283edf0213c37c1a29"
 dependencies = [
  "unicode-xid",
 ]