Extend shared simdutf flag to v8

[kapouer]

What is the problem this feature will solve?

configure.py has --shared-simdutf* flags, but now v8 embeds another copy of simdutf as well.

What is the feature you are proposing to solve the problem?

It would be awesome if tools/v8_gypfiles/v8.gyp was updated to allow linking v8 to the shared simdutf copy.

What alternatives have you considered?

No response