GH-49921: [C++] Bump xsimd to 14.2.0 #6586

Job	Run time
check-labels / Check labels	26s
JNI macOS	37m 53s
ODBC Linux	4m 8s
AMD64 Alpine Linux	42m 3s
ODBC Windows	39m 56s
ODBC release ARM64 macOS 14	55m 44s
AMD64 Ubuntu Large Memory Tests	50m 51s
ODBC debug AMD64 macOS 15-intel	1h 15m 16s
ODBC release AMD64 macOS 15-intel	1h 9m 59s
JNI ubuntu-24.04-arm arm64v8	4m 48s
AMD64 Debian C++23	23m 8s
AMD64 Ubuntu Meson	56m 11s
JNI ubuntu-latest amd64	5m 23s
ODBC debug ARM64 macOS 14	31m 10s
ARM64 Windows 11 MSVC / windows	34m 12s
ODBC release	0s
ODBC nightly	0s
report-extra-cpp	0s
	8h 51m 8s

Provide feedback