Tests

Bump third_party/openthread/repo from `102a631` to `1d81283` #885

Job	Run time
REPL Tests - Darwin	0s
REPL Tests - Linux	41m 33s
Test Suites - Darwin (no-ble-asan-clang)	21m 57s
Test Suites - Linux (no-ble-tsan-clang)	1h 7m 28s
	2h 10m 58s

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