fix: validating required arguments in all cases

Author: evilsocket

dyana/loaders/loader.py

@@ -72,6 +72,10 @@ def __init__(
                 if args:
                     self.build_args = self.settings.parse_build_args(args)
                     self.args = self.settings.parse_args(args)
+
+                for arg in self.settings.args:
+                    if arg.required and not self.args:
+                        raise ValueError(f"Argument --{arg.name} is required")
         else:
             self.settings = None