Bump third_party/pigweed/repo from `9e4bfb9` to `17663e0` #503

Job	Run time
Build on Linux (fake, gcc_release, clang, simulated)	39m 54s
Build on Linux (gcc_debug)	59m 13s
Build on Darwin (clang, python_lib, simulated)	1h 36m 52s
Build on Linux (coverage)	13m 58s
Build on Linux (python_lib)	26m 17s
	3h 56m 14s

Provide feedback