Update wana_kana to 4.0.0

[tats-u]

• https://github.com/meilisearch/meilisearch/pull/3588#issuecomment-1543840378
• https://github.com/PSeitz/wana_kana_rust/issues/13
• https://github.com/meilisearch/meilisearch/pull/3588/commits/0fbda6383b13170ce04c1bd002c643812d32bb22
• https://github.com/orgs/meilisearch/discussions/532#discussioncomment-9999921

wana_kana 3.x easily panics and make it difficult to be used in the Meilisearch core. Its author says it doesn't panic in v4.0.0., so we should update it.