refactor(workdir): simplify review follow-ups

Signed-off-by: Matthew Grossman <mgrossman@nvidia.com>

crates/openshell-driver-docker/src/lib.rs

@@ -2195,7 +2195,6 @@ fn build_environment_for_oci_user(
             user_env.extend(template.environment.clone());
         }
         user_env.extend(spec.environment.clone());
-        user_env.remove(openshell_core::sandbox_env::OCI_WORKSPACE_IDENTITY);
         environment.extend(user_env.clone());
         if !user_env.is_empty()
             && let Ok(json) = serde_json::to_string(&user_env)

crates/openshell-driver-podman/src/container.rs

@@ -522,7 +522,6 @@ fn build_env(
             user_env.insert(k.clone(), v.clone());
         }
     }
-    user_env.remove(openshell_core::sandbox_env::OCI_WORKSPACE_IDENTITY);
     env.extend(user_env.clone());
     if !user_env.is_empty()
         && let Ok(json) = serde_json::to_string(&user_env)

crates/openshell-supervisor-process/src/process.rs

@@ -1409,12 +1409,7 @@ pub fn validate_oci_workspace_as_process_identity(
     supplementary_gids.dedup();
 
     if nix::unistd::geteuid().is_root() {
-        #[cfg(not(any(
-            target_os = "macos",
-            target_os = "ios",
-            target_os = "haiku",
-            target_os = "redox"
-        )))]
+        #[cfg(target_os = "linux")]
         nix::unistd::setgroups(&supplementary_gids).into_diagnostic()?;
         nix::unistd::setgid(gid).into_diagnostic()?;
         nix::unistd::setuid(uid).into_diagnostic()?;