cargo: bump syn from 1.0.64 to 1.0.67

Bumps [syn](https://github.com/dtolnay/syn) from 1.0.64 to 1.0.67.
- [Release notes](https://github.com/dtolnay/syn/releases)
- [Commits](https://github.com/dtolnay/syn/compare/1.0.64...1.0.67)

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

Cargo.lock

@@ -3578,9 +3578,9 @@ dependencies = [
 
 [[package]]
 name = "syn"
-version = "1.0.64"
+version = "1.0.67"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "3fd9d1e9976102a03c542daa2eff1b43f9d72306342f3f8b3ed5fb8908195d6f"
+checksum = "6498a9efc342871f91cc2d0d694c674368b4ceb40f62b65a7a08c3792935e702"
 dependencies = [
  "proc-macro2",
  "quote",

deltachat_derive/Cargo.toml

@@ -9,5 +9,5 @@ license = "MPL-2.0"
 proc-macro = true
 
 [dependencies]
-syn = "1.0.13"
+syn = "1.0.67"
 quote = "1.0.2"