Fix Python 3.8 compatibility

Dockerfile

@@ -2,6 +2,7 @@
 FROM ubuntu:24.04
 
 # Install required libraries
+ENV DEBIAN_FRONTEND=noninteractive
 RUN apt-get update
 RUN apt-get install -y apt-utils dialog file git vim python3 python3-dev \
                        build-essential make gcc wget gzip libgsl-dev \

data/stars/starCataloguesMerge/star_descriptor.py

@@ -27,7 +27,7 @@
 import logging
 
 from math import hypot, pi, cos
-from typing import Dict, List, Optional, Tuple
+from typing import Dict, List, Optional, Tuple, Union
 
 
 # Memory efficient data structure used for storing data about stars
@@ -154,14 +154,14 @@ def add_catalogue_name(self, new_name: str) -> None:
             self.names_catalogue_ref = []
         self.names_catalogue_ref.append(new_name)
 
-    def magnitude_dictionary(self) -> Dict[str, Dict[str, float | Optional[str]]]:
+    def magnitude_dictionary(self) -> Dict[str, Dict[str, Union[float, Optional[str]]]]:
         """
         Return a dictionary of all available magnitudes for this star.
 
         :return:
             dict
         """
-        output: Dict[str, Dict[str, float | Optional[str]]] = {}
+        output: Dict[str, Dict[str, Union[float, Optional[str]]]] = {}
         if self.mag_V is not None:
             output['V'] = {'value': self.mag_V, 'source': self.mag_V_source}
         if self.mag_BT is not None:

dataFetch.py

@@ -30,7 +30,7 @@
 import sys
 import logging
 
-from typing import Dict, List
+from typing import Dict, List, Union
 
 
 def fetch_file(web_address: str, destination: str, force_refresh: bool = False) -> bool:
@@ -124,7 +124,7 @@ def fetch_required_files(refresh: bool) -> None:
         None
     """
     # List of the files we require
-    required_files: List[Dict[str, str | bool]] = [
+    required_files: List[Dict[str, Union[str, bool]]] = [
         # Definitions of constellation boundaries
 #       {
 #           'url': 'https://cdsarc.u-strasbg.fr/ftp/VI/49/bound_20.dat.gz',