loongarch64-none*: Remove environment component from llvm target

Author: heiher

compiler/rustc_target/src/spec/loongarch64_unknown_none_softfloat.rs

@@ -3,7 +3,7 @@ use super::{Target, TargetOptions};
 
 pub fn target() -> Target {
     Target {
-        llvm_target: "loongarch64-unknown-none-softfloat".into(),
+        llvm_target: "loongarch64-unknown-none".into(),
         pointer_width: 64,
         data_layout: "e-m:e-p:64:64-i64:64-i128:128-n64-S128".into(),
         arch: "loongarch64".into(),