Resolve VVL warning on not consuming vertex attribute at location 3

Description

The extensions sample push_descriptors fires a VVL performance warning on not consuming the vertex attribute at location 3 in its vertex shader. This PR simply removes that fourth vertex attribute in the vertex_input_attributes on creating the graphics pipeline.

Build tested on Win10 with VS2022. Run tested on Win10 with NVidia GPU.

General Checklist:

Please ensure the following points are checked:

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

Note: The Samples CI runs a number of checks including:
- [x] I have updated the header Copyright to reflect the current year (CI build will fail if Copyright is out of date)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:

[x] I have tested the sample on at least one compliant Vulkan implementation
[ ] If the sample is vendor-specific, I have tagged it appropriately
[x] 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

KhronosGroup / Vulkan-Samples