expat: fix CVE-2024-45492

An issue was discovered in libexpat before 2.6.3. nextScaffoldPart in xmlparse.c can have
an integer overflow for m_groupSize on 32-bit platforms (where UINT_MAX equals SIZE_MAX).

(From OE-Core rev: 5b31e7f46ab05aca48f4fb11c558ff990e772c9e)

Signed-off-by: Archana Polampalli <archana.polampalli@windriver.com>
Signed-off-by: Steve Sakoman <steve@sakoman.com>