Use unix pipe to capture environment variables (#32136)

The use of `NamedTempFile` in #31799 was not secure and could
potentially cause write permission issues (see [this
comment](https://github.com/zed-industries/zed/issues/29528#issuecomment-2939672433)).
Therefore, it has been replaced with a Unix pipe.

Release Notes:
- N/A

crates/project/src/environment.rs

@@ -249,7 +249,7 @@ async fn load_shell_environment(
     use util::shell_env;
 
     let dir_ = dir.to_owned();
-    let mut envs = match smol::unblock(move || shell_env::capture(Some(dir_))).await {
+    let mut envs = match smol::unblock(move || shell_env::capture(&dir_)).await {
         Ok(envs) => envs,
         Err(err) => {
             util::log_err(&err);