[PULP-2548] Add key-signed attestation verification support - #1327

On December 2, 2026, GitHub will restrict `pull_request_target` on public repositories by default. To continue allowing the event trigger, configure an Actions policy. Learn more: https://gh.io/securely-using-pull_request_target#default-policy-for-pull_request_target

Failed to save: Unable to reserve cache with key setup-uv-2-x86_64-unknown-linux-gnu-ubuntu-24.04-3.14.9-pruned-190d7af55122914ea10fafc608fee6d1cac8ec0461303f751d4b0e91e8409c49, another job may be creating this cache.

Cache reservation failed: cache write denied: token has no writable scopes