Revert "update release / changelog"

[r-n-o]

This reverts commit 7d9ddc3.

Bumping crates manually confuses release-plz, which we use for automated releases. Since this happened release-plz hasn't been working because it (helpfully!) thinks we've manually released our crates:

2026-02-20T22:23:27.077541Z  INFO determining next version for turnkey_api_key_stamper 0.6.0
2026-02-20T22:23:27.165205Z  INFO turnkey_api_key_stamper: the local package has already a different version with respect to the registry package, so release-plz will not update it
2026-02-20T22:23:27.180836Z  INFO determining next version for turnkey_client 0.6.0
2026-02-20T22:23:27.262214Z  INFO turnkey_client: the local package has already a different version with respect to the registry package, so release-plz will not update it
2026-02-20T22:23:27.271887Z  INFO determining next version for turnkey_enclave_encrypt 0.6.0
2026-02-20T22:23:27.359546Z  INFO turnkey_enclave_encrypt: the local package has already a different version with respect to the registry package, so release-plz will not update it
2026-02-20T22:23:27.376174Z  INFO determining next version for turnkey_proofs 0.6.0
2026-02-20T22:23:27.463270Z  INFO turnkey_proofs: the local package has already a different version with respect to the registry package, so release-plz will not update it