Release v0.8.0

chore: bump to 0.8.0, update ic_cose/cose2/pkcs8 deps

- ic_cose/ic_cose_types 0.10 -> 0.11, cose2 0.4 -> 0.5, pkcs8 0.10 -> 0.11
- ic_tee_cli: migrate identity-new to pkcs8 0.11 PrivateKeyInfoRef API

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>