[mlir][bazel]: Remove GPU dialect deps from MemRefTransforms (#205624)
This change removes dead GPU dependencies (`GPUDialect` and
`NVGPUDialect`) from the `MemRefTransforms` target. These dependencies
are not needed by the transforms themselves and greatly increase the
build time (e.g., NVVMDialect.cpp alone requires two minutes to build).
This aligns the bazel build with the CMake configuration.