Avoid always triggering migration code on SqliteZip initialisation

[GeigerJ2]

Because of this code:

aiida-core/src/aiida/storage/sqlite_zip/backend.py

Lines 120 to 144 in f995713

	@classmethod
	def initialise(cls, profile: 'Profile', reset: bool = False) -> bool:
	"""Initialise an instance of the ``SqliteZipBackend`` storage backend.
	:param reset: If ``true``, destroy the backend if it already exists including all of its data before recreating
	and initialising it. This is useful for example for test profiles that need to be reset before or after
	tests having run.
	:returns: ``True`` if the storage was initialised by the function call, ``False`` if it was already initialised.
	"""
	validate_sqlite_version()
	from archive_path import ZipPath
	filepath_archive = Path(profile.storage_config['filepath'])
	if filepath_archive.exists() and not reset:
	from .migrator import migrate
	# The archive exists but ``reset == False``, so we try to migrate to the latest schema version. If the
	# migration works, we replace the original archive with the migrated one.
	with tempfile.TemporaryDirectory() as dirpath:
	filepath_migrated = Path(dirpath) / 'migrated.zip'
	LOGGER.report(f'Migrating existing {cls.__name__}')
	migrate(filepath_archive, filepath_migrated, cls.version_head())
	shutil.move(filepath_migrated, filepath_archive) # type: ignore[arg-type]
	return False

the migrate function is always called, even if the archive version is recent and wouldn't require migration.