Fix build fortress + jammy

[nkoenig]

🦟 Bug fix

Summary

I was attempting to build Fortress on Jammy, and rand into:

 GraphicsAPI.hh:31:10: warning: elaborated-type-specifier for a scoped enum must not use the ‘class’ keyword

followed by:

GraphicsAPI.hh:31:55: error: found ‘:’ in nested-name-specifier, expected ‘::’
   31 |     enum class IGNITION_RENDERING_VISIBLE GraphicsAPI : uint16_t

The fix was to include the header file where uint16_t is defined.

I'm using gcc 13.2.0.

Checklist

• Signed all commits for DCO
• Added tests
• Updated documentation (as needed)
• Updated migration guide (as needed)
• Consider updating Python bindings (if the library has them)
• codecheck passed (See contributing)
• All tests passed (See test coverage)
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