clang-format: don't format glsl files
VTK uses comments not formatted how clang-format wants them. Now that the GLSL files are at least largely conforming, drop them from formatting.
Cc: @jpouderoux
VTK uses comments not formatted how clang-format wants them. Now that the GLSL files are at least largely conforming, drop them from formatting.
Cc: @jpouderoux