Bump third_party/pigweed/repo from `1f12d06` to `63ebec1` #908

Job	Run time
Build on Darwin (clang, python_lib, simulated)	3m 0s
Build on Linux (fake, gcc_release, clang, simulated)	1h 42m 10s
Build on Linux (coverage)	16m 52s
Build on Linux (gcc_debug)	1h 11m 58s
Build on Linux (python lighting-app)	2m 21s
Build on Linux (python_lib)	3m 6s
	3h 19m 27s

Provide feedback