fix: downgrade to ICU 74

[dunglas]

What does this PR do?

It doesn't look currently possible to use ICU 75 with PHP because this version requires C++ 17.
php/php-src#14002 and #414 will fix the issue. In the meantime, we have to downgrade ICU to v74.

Checklist before merging

If your PR involves the changes mentioned below and completed the action, please tick the corresponding option.
If a modification is not involved, please skip it directly.

• If it's a extension or dependency update, make sure adding related extensions in src/global/test-extensions.php.
• If you changed the behavior of static-php-cli, add docs in static-php/static-php-cli-docs .
• If you updated config/xxxx.json content, run bin/spc dev:sort-config xxx.

[dunglas]

Closing in favor of #414.