icu: bump to 70.1

icu: bump to 70.1

ICU 70 released. It updates to Unicode 14, including new characters, scripts, emoji, and corresponding API constants. ICU 70 adds support for emoji properties of strings. It also updates to CLDR 40 locale data with many additions and corrections. ICU 70 also includes many other bug fixes and enhancements, especially for measurement unit formatting, and it can now be built and used with C++20 compilers.

This change will require minor modifications in php7 and php8.

Signed-off-by: Hirokazu MORIKAWA <morikw2@gmail.com>