ci: Rename items specific to Windows + MSVCRT

This is necessary to prepare for introducing the new Windows + UCRT
script and jobs.

ci/test/00_setup_env_win64.sh

@@ -1,22 +0,0 @@
-#!/usr/bin/env bash
-#
-# Copyright (c) 2019-present 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 CONTAINER_NAME=ci_win64
-export CI_IMAGE_NAME_TAG="mirror.gcr.io/ubuntu:24.04"  # Check that https://packages.ubuntu.com/noble/g++-mingw-w64-x86-64-posix (version 13.x, similar to guix) can cross-compile
-export HOST=x86_64-w64-mingw32
-export PACKAGES="g++-mingw-w64-x86-64-posix nsis"
-export RUN_UNIT_TESTS=false
-export RUN_FUNCTIONAL_TESTS=false
-export GOAL="deploy"
-export BITCOIN_CONFIG="\
-  --preset=dev-mode \
-  -DENABLE_IPC=OFF \
-  -DWITH_USDT=OFF \
-  -DREDUCE_EXPORTS=ON \
-  -DCMAKE_CXX_FLAGS='-Wno-error=maybe-uninitialized' \
-"