Bump third_party/mbedtls/repo from `0834c59` to `2153b1b` #99432

Job	Run time
REPL Tests - Linux	1h 57m 30s
REPL Tests - Darwin	0s
Test Suites - Darwin (no-ble-no-shell-asan-clang)	1h 19m 46s
Test Suites - Linux (no-ble-no-shell-tsan-clang)	1h 47m 4s
Test Suites - Darwin (no-ble-no-shell-tsan-clang)	1h 53m 14s
	6h 57m 34s

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