Deleting Oak 2019, 2020, and 2021 shards

[Phil Porada]

This is a follow up to our previous attempt to retire old Oak shards https://groups.google.com/a/chromium.org/g/ct-policy/c/madcUcQZ1IQ

On June 27th, 2022 we're going to be deleting the following CT shards. These particular shards have long since stopped accepting new certificate issuances.

Shards:
  - Oak 2019
  - Oak 2020
  - Oak 2021
 
If you require any data from these old shards, Google has graciously provided the following read-only log mirrors for production logs (e.g. Oak). Users are welcome to continue retrieving shard data from these mirrors. Please keep in mind that Google has not published any SLA or guarantee about the lifecycle of these mirrors.
- https://ct.googleapis.com/logs/eu1/mirrors/letsencrypt_oak2019/
- https://ct.googleapis.com/logs/eu1/mirrors/letsencrypt_oak2020/
- https://ct.googleapis.com/logs/eu1/mirrors/letsencrypt_oak2021/

[Phil Porada]

TIMBERRRRR!!!

Oak 2019, 2020, and 2021 shards have been deleted.

[Amir Omidi]

Congrats! Excellent to see that these shards that fulfilled a great objective during the past few years are now retired, and I bet it was a great feeling of relief being done with them all.