feat: Enable support for yaml configuration files for DatagatewayAPI

BREAKING CHANGE: Remove support for json configuration files

datagateway_api/src/common/config.py

@@ -1,4 +1,4 @@
-import json, yaml
+import yaml
 import logging
 from pathlib import Path
 import sys
@@ -186,17 +186,9 @@ def load(cls, path=Path(__file__).parent.parent.parent / "config.yaml"):
         :param path: path to the configuration file
         :return: APIConfig model object that contains the config data
         """
-        log = logging.getLogger()
         try:
-            jpath = path.parent / "config.json" #Maybe move this to parameters? Will doing it like this break anything?
-            if path.exists():
-                with open(path, encoding="utf-8") as target:
+            with open(path, encoding="utf-8") as target:
                     data = yaml.safe_load(target)
-
-            elif jpath.exists():
-                log.warn("DEPRECATED: Using a JSON config file is deprecated and may be removed in an upcoming version. Please use a yaml config file instead.") #Does this message need to exist?
-                with open(jpath, encoding="utf-8") as target:
-                    data = json.load(target)
             return cls(**data)
         except (IOError, ValidationError) as error:
             sys.exit(f"An error occurred while trying to load the config data: {error}")