values: Don't allow translated strings in arrays

Gtk.Builder has no way to translate individual strings in a string
array, so don't allow it in the syntax.

blueprintcompiler/language/values.py

@@ -452,6 +452,14 @@ class ArrayValue(AstNode):
                                 range=quoted_literal.range,
                             )
                         )
+                elif isinstance(value.child, Translated):
+                    errors.append(
+                        CompileError(
+                            "Arrays can't contain translated strings",
+                            range=value.child.range,
+                        )
+                    )
+
             if len(errors) > 0:
                 raise MultipleErrors(errors)
 

tests/sample_errors/translated_string_array.blp

@@ -0,0 +1,7 @@
+using Gtk 4.0;
+
+StringList {
+  strings: [
+    _("Test")
+  ];
+}

tests/sample_errors/translated_string_array.err

@@ -0,0 +1 @@
+5,5,9,Arrays can't contain translated strings