Fix regression in renode container

[danielinux]

• tagging to previous 1.15 version since 1.16 seems broken
• Enforcing nrf52 config set/restore for renode runs

[Copilot]

Pull request overview

Pins the Renode container image to a known-good version and makes Renode test runs enforce a specific nRF52 build configuration while restoring any pre-existing repo .config afterward.

Changes:

• Pin Renode container base image to antmicro/renode:1.15.3 to avoid regressions in newer images.
• Add .config backup/restore flow to renode-test-update.sh and force config/examples/nrf52840.config for Renode runs.

Reviewed changes

Copilot reviewed 2 out of 2 changed files in this pull request and generated 1 comment.

File	Description
tools/scripts/renode-test-update.sh	Backs up/restores .config and forces the nRF52840 example config before building/running Renode tests.
tools/renode/Dockerfile	Pins Renode base image to version 1.15.3 instead of latest.

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[Copilot]

prepare_build_config can accidentally delete the user’s pre-existing .config if mktemp or cp .config "$RENODE_CONFIG_BACKUP" fails (because RENODE_CONFIG_BACKUP is set before verifying the backup file was successfully created). On exit, restore_build_config will then fall back to rm -f .config, losing the original configuration. Consider only setting RENODE_CONFIG_BACKUP after a successful copy (or aborting the script on backup failure) so the original .config is never destroyed.

Suggested change

	RENODE_CONFIG_BACKUP=$(mktemp /tmp/wolfboot-renode-config.XXXXXX)
	cp .config "$RENODE_CONFIG_BACKUP"
	local backup
	backup=$(mktemp /tmp/wolfboot-renode-config.XXXXXX) || {
	echo "Failed to create temporary backup for existing .config; aborting." >&2
	exit 1
	}
	if ! cp .config "$backup"; then
	echo "Failed to backup existing .config to $backup; aborting." >&2
	rm -f "$backup"
	exit 1
	fi
	RENODE_CONFIG_BACKUP="$backup"