Prevent context canceled errors from being permanent in authorizer
Prevent context canceled errors from being permanent in authorizer

Signed-off-by: Vlad A. Ionescu <ce0d2938f112d18492554a817fa78089a05de5da@users.noreply.github.com>

Check if context is canceled before returning cached token or err.

Signed-off-by: Vlad A. Ionescu <ce0d2938f112d18492554a817fa78089a05de5da@users.noreply.github.com>

Fix possible race conditions

Signed-off-by: Vlad A. Ionescu <ce0d2938f112d18492554a817fa78089a05de5da@users.noreply.github.com>

Fix block

Signed-off-by: Vlad A. Ionescu <ce0d2938f112d18492554a817fa78089a05de5da@users.noreply.github.com>

tonistiigi/buildkit_poc,tonistiigi/buildkit_poc