Revert required encryption on CI runner tokens

Merged Stan Hu requested to merge revert-a6875e5f into master

This reverts !31800 (merged) because there may be runners that have not had their tokens encrypted, and that merge request breaks those runners.

We should issue another migration/check to ensure that Ci::Runner#ensure_token has been run before we make this required.

Relates to #245322 (closed)

Edited by Stan Hu