Roll Vulkan-Headers from 8ed12a9178e7 to a4f8ada9f4f9 (5 revisions)

https://chromium.googlesource.com/external/github.com/KhronosGroup/Vulkan-Headers/+log/8ed12a9178e7..a4f8ada9f4f9

2025-09-25 33833587+M2-TE@users.noreply.github.com fixed faulty var name..
2025-09-25 33833587+M2-TE@users.noreply.github.com propagate DVULKAN_HEADERS_DISABLE_MODULE_STD value to CTests
2025-09-25 33833587+M2-TE@users.noreply.github.com reset module flag
2025-09-25 33833587+M2-TE@users.noreply.github.com set VULKAN_HEADERS_DISABLE_MODULE_STD=ON in CI, while tooling is unable to handle import std
2025-09-25 33833587+M2-TE@users.noreply.github.com add option VULKAN_HEADERS_DISABLE_MODULE_STD to avoid automatic use of import std

If this roll has caused a breakage, revert this CL and stop the roller
using the controls here:
https://autoroll.skia.org/r/vulkan-headers-vulkan-deps-autoroll
Please CC angle-team@google.com,geofflang@google.com on the revert to ensure that a human
is aware of the problem.

To report a problem with the AutoRoller itself, please file a bug:
https://issues.skia.org/issues/new?component=1389291&template=1850622

Documentation for the AutoRoller is here:
https://skia.googlesource.com/buildbot/+doc/main/autoroll/README.md

Tbr: geofflang@google.com
Change-Id: I9dbb06c2a776f431face78506f4907418cefdb5e
Reviewed-on: https://chromium-review.googlesource.com/c/vulkan-deps/+/6987243
Bot-Commit: chromium-autoroll <chromium-autoroll@skia-public.iam.gserviceaccount.com>

• DEPS[diff]
• vulkan-headers/src[diff]