fix(examples): offscreen pins compat.vulkan 1.4.357.1

The example names `compat.vulkan-runtime` itself, under a cfg(linux)
predicate, and compares that pin against the one recorded in its installed copy
of `compat.vulkan`. 1.4.357.0 records 2026.09.07; 1.4.357.1 is the version
whose install records 2026.09.10. See mcpplibs/mcpp-index#381.

Author: speak-agent

examples/10-graphics/offscreen/mcpp.toml

@@ -28,7 +28,7 @@ plugins = { version = "0.5.2", features = ["rules-spirv"], host-module = true }
 # seam work: the CPU leg below is selected by the accelerator, and only the
 # packages are unconditional.
 [dependencies.compat]
-vulkan = "1.4.357.0"
+vulkan = "1.4.357.1"
 
 # The adapter that makes the host's own ICDs reachable from a binary running
 # under mcpp's private loader. An OS predicate, which IS allowed, and a Linux