Invalid shader gen if mesh contains "float1" in UVs

#### System Information
- Ogre Version: 4.0
- Operating System / Platform: Any
- RenderSystem: GL & Vulkan for sure. Likely affects D3D11 and Metal
- GPU: any

#### Detailled description

Load a mesh with a single-component `VES_TEXTURE_COORDINATES`.

See https://forums.ogre3d.org/viewtopic.php?p=557559#p557559

#### Ogre.log


#### Callstack