Bump third_party/libwebsockets/repo from `a1cbc02` to `816544f` #66300

Job	Run time
REPL Tests - Darwin	0s
REPL Tests - Linux	43m 8s
Test Suites - Darwin (no-ble-asan-clang)	1h 9m 45s
Test Suites - Linux (no-ble-tsan-clang)	1h 41m 54s
Test Suites - Darwin (no-ble-tsan-clang)	2h 8m 41s
	5h 43m 28s

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