lint: Use $CI_RETRY_EXE when building ./ci/lint_imagefile

Previous code was confusing and brittle. For example, the full import
"source ./ci/test/00_setup_env.sh" and $PATH overwrite was not needed.

Fix it by simply copying the exe to /ci_retry and use that in
$CI_RETRY_EXE.

This is also a fix, because previously ci/lint_imagefile did use an
empty $CI_RETRY_EXE.

Author: MarcoFalke

ci/lint/04_install.sh

@@ -1,12 +1,12 @@
 #!/usr/bin/env bash
 #
-# Copyright (c) 2018-2022 The Bitcoin Core developers
+# Copyright (c) 2018-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
 
-export PATH=$PWD/ci/retry:$PATH
+export CI_RETRY_EXE="/ci_retry --"
 
 ${CI_RETRY_EXE} apt-get update
 # Lint dependencies:

ci/lint_imagefile

@@ -9,6 +9,7 @@ FROM debian:bookworm
 ENV DEBIAN_FRONTEND=noninteractive
 ENV LC_ALL=C.UTF-8
 
+COPY ./ci/retry/retry /ci_retry
 COPY ./.python-version /.python-version
 COPY ./ci/lint/container-entrypoint.sh /entrypoint.sh
 COPY ./ci/lint/04_install.sh /install.sh

ci/lint_run_all.sh

@@ -1,12 +1,12 @@
 #!/usr/bin/env bash
 #
-# Copyright (c) 2019-2020 The Bitcoin Core developers
+# 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
 
-set -o errexit; source ./ci/test/00_setup_env.sh
+cp "./ci/retry/retry" "/ci_retry"
 set -o errexit; source ./ci/lint/04_install.sh
 set -o errexit
 ./ci/lint/06_script.sh