Pin Vulkan v3.1.3 and use i32 FD outputs in particles

[antono3]

Summary

Pin the particle example's required Vulkan dependency and CI checkout to released antono2.vulkan@v3.1.3. Initialize Vulkan external-memory and semaphore FD outputs as i32, matching the raw Vulkan C int* ABI corrected in antono2/vulkan#58.

The separate advisory dependency-master lane remains in place.

Verification

• V 0.5.2 + GCC against the v3.1.3 tag: headless particle smoke completed zero-copy memory exchange and Vulkan–OpenCL semaphore handoff.
• V 0.5.2 + TCC against matching sources: same zero-copy smoke passed.
• Current V3 with local v3: use emitted fixed-array names in function pointers vlang/v#28902 and v3: pass dynamic array data pointers without autoref vlang/v#28903 compiler fixes: particle smoke completed the same zero-copy exchange. The negative-float output formatting defect is tracked separately in test: cover negative fixed float interpolation vlang/v#28904.
• git diff --check passes.