travis: Remove s390x

ci/test/00_setup_env_s390x_host.sh

@@ -1,14 +0,0 @@
-#!/usr/bin/env bash
-#
-# Copyright (c) 2019-2020 The Bitcoin Core developers
-# Distributed under the MIT software license, see the accompanying
-# file COPYING or http://www.opensource.org/licenses/mit-license.php.
-
-export LC_ALL=C.UTF-8
-
-export HOST=s390x-linux-gnu
-export NO_DEPENDS=1
-export BITCOIN_CONFIG="--with-incompatible-bdb --enable-reduce-exports"
-export RUN_UNIT_TESTS=true
-export RUN_FUNCTIONAL_TESTS=true
-export GOAL="install"