build: Cleanup toolchain fetch path
build: Cleanup toolchain fetch path

To support both pre-installed tarball in CI docker and fetch

Change-Id: I3d27fa3f09b0019aca507c82961362bfc31b64e7
GitOrigin-RevId: cb20b2d6e250df48cd8b2bc604c7d787c74cf20f

AmbiML/sparrow-build