fix(runtime): musl build — gate RTLD_DEEPBIND to glibc only (v0.5.854)

`libc::RTLD_DEEPBIND` is glibc-only; the previous `target_os="linux"`
cfg matched musl too, which broke the linux-musl release build.
Adds `target_env="gnu"` to restrict the binding. Musl is otherwise
unaffected: it just doesn't expose RTLD_DEEPBIND through os.constants.dlopen.

Author: proggeramlug

CLAUDE.md

@@ -8,7 +8,7 @@ This file provides guidance to Claude Code (claude.ai/code) when working with co
 
 Perry is a native TypeScript compiler written in Rust that compiles TypeScript source code directly to native executables. It uses SWC for TypeScript parsing and LLVM for code generation.
 
-**Current Version:** 0.5.853
+**Current Version:** 0.5.854
 
 
 ## TypeScript Parity Status