Racecondition when downloading color definition files

[sirno]

Hi,

the following code introduces a racecondition that may trigger when multiple instances of python import ete4 in parallel

ete/ete4/smartview/renderer/layouts/ncbi_taxonomy_layouts.py

Lines 12 to 20 in 254f256

	taxid2color_file = ETE_DATA_HOME + '/taxid2color.json'
	if not os.path.exists(taxid2color_file):
	url = ('https://github.com/etetoolkit/ete-data/raw/main'
	'/layouts/taxid2color.json')
	update_ete_data(taxid2color_file, url)
	with open(taxid2color_file) as handle:
	_taxid2color = json.load(handle)

Similar raceconditions apply for smart2color.json and pfam2color.json.