test(plugins/dotenv): silence S701 on test-only jinja2 autoescape=False

The mode-aware dotenv_quote test renders the filter through a real
jinja2.Environment to exercise the @pass_context branch. The filter
produces shell env-file values, not HTML, so autoescape=True would
mangle `&`, `<`, `>`, `'`, and `"` into HTML entities and break every
assertion. Suppressing bandit S701 here is the correct call -- there
is no XSS surface for a test-suite Environment that templates
KEY=VALUE pairs.

tests/unit/plugins/filter/test_dotenv_quote.py

@@ -72,7 +72,10 @@ class TestDotenvQuoteModeAware(unittest.TestCase):
     """
 
     def setUp(self):
-        env = jinja2.Environment(autoescape=False)
+        # The filter renders shell env-file values, not HTML; autoescape
+        # would replace `&`, `<`, `>`, `'`, `"` with HTML entities and
+        # break every assertion below.
+        env = jinja2.Environment(autoescape=False)  # noqa: S701
         env.filters["dotenv_quote"] = FilterModule().filters()["dotenv_quote"]
         self.env = env