[infra] Update GTX1660 bots to NVIDIA driver 32.0.16.1742 and Windows 11 26H2

The Dell3930 GTX1660 machines were updated to a newer NVIDIA driver and
Windows 11 26H2:
  gpu: 10de:2184-31.0.15.4601 -> 10de:2184-32.0.16.1742
  os:  Windows-11-26100       -> Windows-11-26300

The old driver intermittently failed vkCreateGraphicsPipelines when
Graphite compiled SPIR-V 1.3 pipelines on multiple threads. The
Graphite_Native_Vulkan jobs pass with SPIR-V 1.3 on the updated driver,
which unblocks https://skia-review.googlesource.com/c/skia/+/1391270.

Change-Id: I0813ca885b6354d0f307e94be851c17226a3a7c6
Reviewed-on: https://skia-review.googlesource.com/c/skia/+/1397776
Auto-Submit: Thomas Smith <thomsmit@google.com>
Reviewed-by: Robert Phillips <robertphillips@google.com>
Commit-Queue: Robert Phillips <robertphillips@google.com>
Reviewed-by: Michael Ludwig <michaelludwig@google.com>
Commit-Queue: Michael Ludwig <michaelludwig@google.com>