fix: remove bad feature gating

We do not have a `std` feature, so this causes an error. Before Rust
1.80, this was not an error.

Author: obycode

stacks-common/src/deps_common/httparse/mod.rs

@@ -1280,7 +1280,6 @@ mod tests {
         );
     }
 
-    #[cfg(feature = "std")]
     #[test]
     fn test_std_error() {
         use std::error::Error as StdError;