icu: fix CVE-2025-5222

icu: fix CVE-2025-5222

CVE-2025-5222:
A stack buffer overflow was found in Internationl components for unicode
(ICU ). While running the genrb binary, the 'subtag' struct overflowed
at the SRBRoot::addTag function. This issue may lead to memory
corruption and local arbitrary code execution.

Refer:
https://nvd.nist.gov/vuln/detail/CVE-2025-5222
https://unicode-org.atlassian.net/browse/ICU-22957
https://github.com/unicode-org/icu/commit/2c667e31cfd0b6bb1923627a932fd3453a5bac77

Signed-off-by: Changqing Li <changqing.li@windriver.com>
Signed-off-by: Steve Sakoman <steve@sakoman.com>