Add regression test for Object.getOwnPropertyDescriptors with JSG_INSPECT_PROPERTY #6538

Performance Gate Passed

✅ 70 untouched benchmarks
⏩ 129 skipped benchmarks¹

_{Comparing harris/2026-04-09-getownpropertydescriptors-regression-test (c9767be) with main (32a5758)}

129 benchmarks were skipped, so the baseline results were used instead. If they were deleted from the codebase, click here and archive them to remove them from the performance reports. ↩