chore: macros crate cleanup (#13685)

* Remove unused dependencies from macros crate

* rename macro lib to user_doc

Author: findepi

datafusion-cli/Cargo.lock

@@ -32,11 +32,11 @@ workspace = true
 
 [lib]
 name = "datafusion_macros"
-path = "src/lib.rs"
+# lib.rs to be re-added in the future
+path = "src/user_doc.rs"
 proc-macro = true
 
 [dependencies]
-datafusion-doc = { workspace = true }
 proc-macro2 = "1.0"
 quote = "1.0.37"
 syn = { version = "2.0.79", features = ["full"] }