Improve performance on K3s secrets-encrypt reencrypt

[dereknola]

Is your feature request related to a problem? Please describe.

In the best case (small secrets of only a few bytes) we reencrypt at a rate of ~5 secrets/second. This is painfully slow compared to kubectl replace, which is roughly ~50 secrets/second.

Describe the solution you'd like
Improve performance of the reencrypt secrets stage. Isolate and determine root cause of performance bottlenecks.

Describe alternatives you've considered

Additional context

[aganesh-suse]

Closing based on: #10637 (comment)