Update syn requirement from 1 to 2

Updates the requirements on [syn](https://github.com/dtolnay/syn) to permit the latest version.
- [Release notes](https://github.com/dtolnay/syn/releases)
- [Commits](https://github.com/dtolnay/syn/compare/1.0.0...2.0.26)

---
updated-dependencies:
- dependency-name: syn
  dependency-type: direct:production
...

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

actix-multipart-derive/Cargo.toml

@@ -21,7 +21,7 @@ darling = "0.14"
 parse-size = "1"
 proc-macro2 = "1"
 quote = "1"
-syn = "1"
+syn = "2"
 
 [dev-dependencies]
 actix-multipart = "0.6"

actix-web-codegen/Cargo.toml

@@ -18,7 +18,7 @@ proc-macro = true
 actix-router = "0.5"
 proc-macro2 = "1"
 quote = "1"
-syn = { version = "1", features = ["full", "extra-traits"] }
+syn = { version = "2", features = ["full", "extra-traits"] }
 
 [dev-dependencies]
 actix-macros = "0.2.3"