rsa: remove backwards compat APIs (#1307)

Now that known users of these APIs have migrated to functions calls
with an explicit hash, remove these backward compat APIs.

This will catch any unknown users of these APIs.

pkg/apk/signature/rsa.go

@@ -99,11 +99,3 @@ func RSAVerifyDigest(digest []byte, digestType crypto.Hash, signature []byte, pu
 
 	return nil
 }
-
-// Backwards compat
-func RSASignSHA1Digest(digest []byte, keyFile, passphrase string) ([]byte, error) {
-	return RSASignDigest(digest, crypto.SHA1, keyFile, passphrase)
-}
-func RSAVerifySHA1Digest(digest, signature []byte, publicKey []byte) error {
-	return RSAVerifyDigest(digest, crypto.SHA1, signature, publicKey)
-}