Remove test cases for doubles from varying components test

Remove test cases for doubles from varying components test

Usage of the component layout qualifier (introduced with
ARB_enhanced_layouts) with double types has specific rules and
restrictions (see page 67 of the GLSL 4.60 spec), but the tests
ignore all of these completely and just follow the same code
paths we use for single-precision types, making the resulting
shaders completely bogus.

Remove these tests until we can provide new ones that make
sense for double precision and follow the specs.

Components: OpenGL
VK-GL-CTS issue: 714

Affects:
KHR-GL45.enhanced_layouts.varying_components
KHR-GL46.enhanced_layouts.varying_components

Change-Id: I2d3c1c645f5a18a83feee5c7b28cb023bd255808