Fix acquire semaphore handling for suboptimal swapchains

[CadenXc]

Description

Fixes #1565

vkAcquireNextImageKHR can return VK_SUBOPTIMAL_KHR after acquiring a usable swapchain image and signaling the acquire semaphore. The affected samples treated every non-VK_SUCCESS result as a failed acquisition and immediately returned the semaphore to the recycle pool. The still-signaled semaphore could then be reused by a later acquire operation, triggering a validation error.

Treat VK_SUBOPTIMAL_KHR as a successful acquisition for semaphore ownership purposes. This keeps the semaphore associated with the acquired frame instead of recycling it through the failure path. The Vulkan-Hpp 1.3 path also keeps the fence wait result separate from the acquire result and normalizes the handled acquisition to success.

Affected samples:

• hello_triangle
• hello_triangle_1_3
• hpp_hello_triangle
• hpp_hello_triangle_1_3
• full_screen_exclusive

Testing

• Built the vulkan_samples Debug target successfully on Windows with MSVC/Visual Studio 2026.
• Passed python scripts/copyright.py main.
• Passed git diff --check main...HEAD.
• The exact VK_SUBOPTIMAL_KHR return path could not be reproduced reliably on the available systems. The change follows the Vulkan acquire-result semantics and addresses the semaphore lifecycle reported in Validation error in hello_triangle: semaphore must not be currently signaled. #1565.

General Checklist:

Please ensure the following points are checked:

• My code follows the coding style
• I have reviewed file licenses
• I have commented any added functions (in line with Doxygen)
• I have commented any code that could be hard to understand
• My changes do not add any new compiler warnings
• My changes do not add any new validation layer errors or warnings
• I have used existing framework/helper functions where possible
• My changes do not add any regressions
• I have tested every sample to ensure everything runs correctly
• This PR describes the scope and expected impact of the changes I am making

Note: The Samples CI runs a number of checks including:

• I have updated the header Copyright to reflect the current year (CI build will fail if Copyright is out of date)
• My changes build on Windows, Linux, macOS and Android. Otherwise I have documented any exceptions

If this PR contains framework changes:

• I did a full batch run using the batch command line argument to make sure all samples still work properly

Sample Checklist

If your PR contains a new or modified sample, these further checks must be carried out in addition to the General Checklist:

• I have tested the sample on at least one compliant Vulkan implementation
• If the sample is vendor-specific, I have tagged it appropriately
• I have stated on what implementation the sample has been tested so that others can test on different implementations and platforms
• Any dependent assets have been merged and published in downstream modules
• For new samples, I have added a paragraph with a summary to the appropriate chapter in the readme of the folder that the sample belongs to e.g. api samples readme
• For new samples, I have added a tutorial README.md file to guide users through what they need to know to implement code using this feature. For example, see conditional_rendering
• For new samples, I have added a link to the Antora navigation so that the sample will be listed at the Vulkan documentation site

[CLAassistant]

All committers have signed the CLA.