Bump proc-macro2 from 1.0.103 to 1.0.104

Bumps [proc-macro2](https://github.com/dtolnay/proc-macro2) from 1.0.103 to 1.0.104.
- [Release notes](https://github.com/dtolnay/proc-macro2/releases)
- [Commits](dtolnay/proc-macro2@1.0.103...1.0.104)

---
updated-dependencies:
- dependency-name: proc-macro2
  dependency-version: 1.0.104
  dependency-type: direct:production
  update-type: version-update:semver-patch
...

Signed-off-by: dependabot[bot] <[email protected]>

Author: dependabot[bot]

Cargo.lock

@@ -15,7 +15,7 @@ repository = "https://github.com/killzoner/clappen"
 proc-macro = true
 
 [dependencies]
-proc-macro2 = { version = "1.0.103", default-features = false }
+proc-macro2 = { version = "1.0.104", default-features = false }
 quote = { version = "1.0.42", default-features = false }
 syn = { version = "2.0.111", features = [
   "clone-impls", # for clone() debug only, ideally should be not used