chore: Updated a function to be compatible with setuptools 82

[christophe-ramet]

Linked to PnX-SI/UsersHub#246

Tested in geonature shell :

sql_file = "dashboard.sql"

from importlib.resources import files
resource_file = files("gn_module_dashboard.migrations") / "data" / sql_file
operations = resource_file.read_text(encoding="utf-8")

import pkg_resources
operations2 = pkg_resources.resource_string("gn_module_dashboard.migrations", f"data/{sql_file}").decode("utf-8")
 
operations == operations2
 >> True