Hello!
I am really loving sops, and I've been working on getting it integrated with the 1Password CLI via the SOPS_AGE_KEY_CMD environment variable. However, I (like a lot of people I imagine) am deriving my age key from my SSH private key, and it occurred to me that the age key derivation step could be cut out if a SOPS_AGE_SSH_PRIVATE_KEY_CMD environment variable could be added and set up to work similarly to SOPS_AGE_KEY_CMD.

Would there be interest in accepting this? If so, I'm happy to work on a PR.