Bump third_party/pigweed/repo from `ce0e3e2` to `bc6e04c` #1070

Job	Run time
REPL Tests - Linux	1m 57s
Test Suites - Darwin (no-ble-no-shell-asan-clang)	2m 42s
Test Suites - Linux (no-ble-no-shell-tsan-clang)	1m 47s
Test Suites - Darwin (no-ble-no-shell-tsan-clang)	2m 37s
REPL Tests - Darwin	0s
	9m 3s

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