Update indoc dev-dependency to version 2

Author: dtolnay

Cargo.toml

@@ -19,7 +19,7 @@ ryu = "1.0"
 
 [dev-dependencies]
 automod = "1.0"
-indoc = "1.0"
+indoc = "2.0"
 ref-cast = "1.0"
 rustversion = "1.0"
 serde = { version = "1.0.100", features = ["derive"] }