bwrap-helper: Reuse system’s PATH

Otherwise running in nix-shell does not make the binaries from the
temporary environment available inside the sandbox.

pkgs/bwrap-helper/bwrap-helper.py

@@ -72,11 +72,6 @@ uid = os.getuid()
 gid = os.getgid()
 home = os.getenv("HOME")
 
-path_entries = [
-    f"/etc/profiles/per-user/{username}/bin",
-    "/run/current-system/sw/bin",
-]
-
 argument_groups = {
     "base": (
         True,
@@ -111,11 +106,13 @@ argument_groups = {
     "path": (
         True,
         [
-            *flat_map(ro_bind_try, path_entries),
-            *setenv("PATH", ":".join(path_entries)),
-            *ro_bind_try(
-                "/run/current-system/sw"
-            ),  # not really path, but also libraries etc.
+            *flat_map(
+                ro_bind,
+                [
+                    "/run/current-system/sw",  # not exclusive to path, but also libraries etc.
+                    f"/etc/profiles/per-user/{username}/bin",
+                ],
+            ),
         ],
     ),
     "gui": (