fix: address review feedback on module-name-shadowing test

Clarify "stanza_modules" wording and remove unnecessary 2>&1 redirects
in cram test.

Signed-off-by: Robin Bate Boerop <me@robinbb.com>

Author: robinbb

test/blackbox-tests/test-cases/per-module-lib-deps/module-name-shadowing.t

@@ -1,7 +1,7 @@
 Test that when a stanza's internal module name shadows a library module name,
 the internal module takes precedence. This validates that ocamldep-based
-dependency filtering (which treats names found in stanza_modules as internal)
-correctly reflects the compiler's resolution order.
+dependency filtering (which treats modules defined within the same stanza as
+internal) correctly reflects the compiler's resolution order.
 
 See: https://github.com/ocaml/dune/issues/4572
 
@@ -51,7 +51,7 @@ The build succeeds using the internal Helper:
 The dependencies of main.ml's native compilation show dune__exe__Helper
 (the internal module), not unwrapped_lib's helper:
 
-  $ dune rules --deps _build/default/.main.eobjs/native/dune__exe__Main.cmx 2>&1 | grep In_build_dir
+  $ dune rules --deps _build/default/.main.eobjs/native/dune__exe__Main.cmx | grep In_build_dir
    (File (In_build_dir _build/default/.main.eobjs/byte/dune__exe.cmi))
    (File (In_build_dir _build/default/.main.eobjs/byte/dune__exe__Helper.cmi))
    (File (In_build_dir _build/default/.main.eobjs/byte/dune__exe__Main.cmi))
@@ -64,7 +64,7 @@ The library's Helper.lib_value is not accessible:
   > let () = print_int Helper.lib_value
   > EOF
 
-  $ dune build ./main.exe 2>&1
+  $ dune build ./main.exe
   File "main.ml", line 1, characters 19-35:
   1 | let () = print_int Helper.lib_value
                          ^^^^^^^^^^^^^^^^