Reduce and tighten comments and docstrings across the test suite (#6429)

* Reduce and tighten comments and docstrings in tests

Shorten verbose comments and docstrings across the test suite without
changing any test logic. Remove narration that restates the next line,
collapse long module and test docstrings to a single line, and drop banner
separators. Keep regression context (issue and PR references, run ids),
skip reasons, mocking and timing rationale, license headers, lint and type
directives, and commented-out code.

Comments and docstrings only: an AST signature check confirms no code,
assertions, or string literals changed, and the suite byte-compiles cleanly.

* [pre-commit.ci] auto fixes from pre-commit.com hooks

for more information, see https://pre-commit.ci

---------

Co-authored-by: pre-commit-ci[bot] <66853113+pre-commit-ci[bot]@users.noreply.github.com>

tests/python/test_studio_import_no_torch.py

@@ -1,13 +1,4 @@
-"""End-to-end sandbox tests: Studio modules in isolated no-torch venvs.
-
-Covers:
-- Python 3.12 and 3.13 venv creation (Intel Mac uses 3.12, Apple Silicon/Linux 3.13)
-- data_collators.py loads and dataclasses instantiate without torch
-- chat_templates.py top-level exec works with stubs for relative imports
-- Negative control: prepending 'import torch' fails in no-torch venv
-- Negative control: installing torchao (from overrides.txt) fails in no-torch venv
-- AST structural checks for top-level torch imports
-"""
+"""Sandbox tests: Studio dataset modules load/run in isolated no-torch venvs."""
 
 from __future__ import annotations
 
@@ -48,10 +39,7 @@ def _create_venv(venv_dir: Path, python_version: str) -> Path | None:
 
 @pytest.fixture(params = ["3.12", "3.13"], scope = "module")
 def no_torch_venv(request, tmp_path_factory):
-    """Create a temporary venv at the requested Python version with no torch.
-
-    Parametrized for 3.12 (Intel Mac) and 3.13 (Apple Silicon / Linux).
-    """
+    """Temp no-torch venv, parametrized for 3.12 (Intel Mac) and 3.13 (Apple Silicon / Linux)."""
     if not _has_uv():
         pytest.skip("uv not available")
 
@@ -353,7 +341,7 @@ class TestFormatConversionAST:
                         and child.module
                         and child.module.startswith("torch")
                     ):
-                        # This torch import must be inside a Try node
+                        # This torch import must be inside a Try node.
                         found_in_try = False
                         for try_node in ast.walk(node):
                             if isinstance(try_node, ast.Try):
@@ -524,10 +512,7 @@ class TestNegativeControls:
             os.unlink(temp_file)
 
     def test_torchao_install_fails_no_torch_venv(self, no_torch_venv):
-        """Installing torchao (from overrides.txt) fails in a no-torch venv.
-
-        This proves the overrides.txt skip is necessary for Intel Mac.
-        """
+        """torchao install fails in a no-torch venv: proves the overrides.txt skip is needed."""
         result = subprocess.run(
             [
                 no_torch_venv,
@@ -541,10 +526,10 @@ class TestNegativeControls:
             timeout = 60,
         )
         if result.returncode != 0:
-            # torchao install/resolution failed as expected
+            # torchao install/resolution failed as expected.
             pass
         else:
-            # pip dry-run may not catch dependency issues; verify torch is missing
+            # dry-run may miss dep issues; verify torch is absent instead.
             check = subprocess.run(
                 [no_torch_venv, "-c", "import torch"],
                 capture_output = True,