Update version for the next release (v0.26.1)

[meili-bot]

This PR is auto-generated.

The automated script updates the version of meilisearch-rust to a new version: "v0.26.1"

[meili-bors[bot]]

Build succeeded:

• clippy-check
• integration-tests
• readme-check
• rust-format
• wasm-build
• Yaml linting check