[Bug] identity.rs blocks modern Rust async stack: no support for tokio 1.44+, axum 0.8+, reqwest 0.12

## Summary

The current version of `identity.rs` is pinned to `tokio 1.43` and is not compatible with the latest Rust async ecosystem, including `axum 0.8+` and `reqwest 0.12`. This is blocking integration for projects that need both IOTA identity features and a modern web backend.

## Details

- Our project (wot.id) requires both IOTA identity (via identity.rs) and a modern REST API backend (axum/reqwest/tokio).
- All recent Rust web frameworks (axum 0.8+, reqwest 0.12) require `tokio 1.44+` and are incompatible with the current identity.rs dependency.
- Downgrading axum/reqwest to match identity.rs results in significant code rewrites and loss of ecosystem support.
- Temporarily, we have removed all identity.rs integration from our backend and are waiting for an update to re-enable full IOTA functionality.

## Request

- Please update identity.rs to support `tokio 1.44+` and the latest versions of axum, reqwest, and related async crates.
- If there is a roadmap or timeline for this, please share it with the community.
- If help is needed, we (and likely others) can assist with migration/testing.

## Impact

This issue blocks modern Rust projects from integrating with IOTA identity, and is likely affecting others in the ecosystem as well.

**Thank you for your work!**

Review identity.rs and its dependency declarations, starting with the tokio 1.43 pin and the compatibility constraints involving axum 0.8+ and reqwest 0.12. Determine the required updates and migration checks, then verify that identity.rs works with tokio 1.44+ and the requested async stack.

Written by the indexing model from the issue text.