Use crypto/(hkdf, sha3) instead of golang.org/x/crypto

Go 1.24 brought these from x/crypto into the standard library

Author: HACKERALERT

picocrypt/main.go

@@ -4,8 +4,10 @@ import (
 	"archive/zip"
 	"bytes"
 	"crypto/cipher"
+	"crypto/hkdf"
 	"crypto/hmac"
 	"crypto/rand"
+	"crypto/sha3"
 	"flag"
 	"fmt"
 	"hash"
@@ -25,8 +27,6 @@ import (
 	"golang.org/x/crypto/argon2"
 	"golang.org/x/crypto/blake2b"
 	"golang.org/x/crypto/chacha20"
-	"golang.org/x/crypto/hkdf"
-	"golang.org/x/crypto/sha3"
 	"golang.org/x/term"
 )