Bump proc-macro2 from 1.0.60 to 1.0.63 (#513)

Bumps [proc-macro2](https://github.com/dtolnay/proc-macro2) from 1.0.60 to 1.0.63.
- [Release notes](https://github.com/dtolnay/proc-macro2/releases)
- [Commits](https://github.com/dtolnay/proc-macro2/compare/1.0.60...1.0.63)

---
updated-dependencies:
- dependency-name: proc-macro2
  dependency-type: direct:production
  update-type: version-update:semver-patch
...

Signed-off-by: dependabot[bot] <support@github.com>
Co-authored-by: dependabot[bot] <49699333+dependabot[bot]@users.noreply.github.com>

Cargo.lock

@@ -1286,9 +1286,9 @@ dependencies = [
 
 [[package]]
 name = "proc-macro2"
-version = "1.0.60"
+version = "1.0.63"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "dec2b086b7a862cf4de201096214fa870344cf922b2b30c167badb3af3195406"
+checksum = "7b368fba921b0dce7e60f5e04ec15e565b3303972b42bcfde1d0713b881959eb"
 dependencies = [
  "unicode-ident",
 ]