BUILD: quic: re-enable chacha20_poly1305 for libressl

this reverts d2be9d4c48

LibreSSL implements EVP_chacha20_poly1305() with EVP_CIPHER for every
released version starting with 3.6.0

include/haproxy/quic_tls.h

@@ -118,10 +118,8 @@ static inline const EVP_CIPHER *tls_aead(const SSL_CIPHER *cipher)
 		return EVP_aes_128_gcm();
 	case TLS1_3_CK_AES_256_GCM_SHA384:
 		return EVP_aes_256_gcm();
-#if !defined(LIBRESSL_VERSION_NUMBER)
 	case TLS1_3_CK_CHACHA20_POLY1305_SHA256:
 		return EVP_chacha20_poly1305();
-#endif
 #ifndef USE_OPENSSL_WOLFSSL
 	case TLS1_3_CK_AES_128_CCM_SHA256:
 		return EVP_aes_128_ccm();