feat: enable anonymous OpenPGP key IDs

This was disabled for interoperability in
098084b9a7,
enabling it back now.

src/reaction.rs

@@ -1031,13 +1031,11 @@ Content-Transfer-Encoding: base64\r
         let alice_secret_key = load_self_secret_key(alice).await?;
         let public_keys_for_encryption = vec![alice_public_key, bob_public_key];
         let compress = true;
-        let anonymous_recipients = true;
         let encrypted_payload = pk_encrypt(
             plain_text.as_bytes().to_vec(),
             public_keys_for_encryption,
             alice_secret_key,
             compress,
-            anonymous_recipients,
             SeipdVersion::V2,
         )
         .await?;