fix(tests): narrow span.data before subscripting in commit-SHA tests

`Span.data` is `dict | list[dict] | None`, so `in` and `[]` need an isinstance
guard to satisfy the project-wide pyright run in scripts/lint.

Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>

Author: cyntwang99

tests/lib/core/tracing/processors/test_sgp_tracing_processor.py

@@ -66,6 +66,7 @@ def test_commit_sha_is_not_stamped_without_opt_in(self, monkeypatch):
         env = MagicMock(ACP_TYPE=None, AGENT_NAME=None, AGENT_ID=None, AGENT_VERSION=None)
         span = _make_span()
         _add_source_to_span(span, env)
+        assert isinstance(span.data, dict)
         assert "__commit_sha__" not in span.data
 
     def test_commit_sha_is_stamped_after_opt_in(self, monkeypatch):
@@ -79,6 +80,7 @@ def test_commit_sha_is_stamped_after_opt_in(self, monkeypatch):
             env = MagicMock(ACP_TYPE=None, AGENT_NAME=None, AGENT_ID=None, AGENT_VERSION=None)
             span = _make_span()
             _add_source_to_span(span, env)
+            assert isinstance(span.data, dict)
             assert span.data["__commit_sha__"] == sha
         finally:
             code_revision.disable()