`usdchecker` tests depend on `usdShaders` plugin, causing test failures when building with `--no-imaging`

[nvmkuruc]

Description of Issue

usdchecker now has tests that depend on usdShaders, introducing an (indirect) dependency on imaging.

This means that tests cannot successfully complete when building without imaging.

Steps to Reproduce

1. python3 ./build_scripts/build_usd.py --no-imaging --no-materialx --no-examples --tests <INSTALL DIRECTORY>
2. Run ctest -R testUsd --output-on-failure in the <INSTALL DIRECTORY>/build/usd directory
3. The following tests should fail.

The following tests FAILED:
        571 - testUsdUtilsCreateNewUsdzPackageEditInPlace (Failed)
        610 - testUsdChecker1 (Failed)
        611 - testUsdChecker2 (Failed)
        612 - testUsdChecker3 (Failed)
        613 - testUsdChecker4 (Failed)
        614 - testUsdChecker5 (Failed)
        622 - testUsdChecker13 (Failed)

The error messages should all be associated with the ShaderPropertyTypeConformanceChecker

Shader </World/material/nodeGraph/PreviewShader> has invalid shader node.  (fails 'ShaderPropertyTypeConformanceChecker')

System Information (OS, Hardware)

WSL2

Package Versions

Build Flags

[jesschimein]

Filed as internal issue #USD-9590