Revert "Implemented variable substitution for nested structures (#3665)"

This reverts commit dda6937.

cumulusci/core/tasks.py

@@ -135,26 +135,13 @@ def _init_options(self, kwargs):
             self.options.update(kwargs)
 
         # Handle dynamic lookup of project_config values via $project_config.attr
-        def process_options(option):
-            if isinstance(option, str):
-                return PROJECT_CONFIG_RE.sub(
+        for option, value in self.options.items():
+            if isinstance(value, str):
+                value = PROJECT_CONFIG_RE.sub(
                     lambda match: str(self.project_config.lookup(match.group(1), None)),
-                    option,
+                    value,
                 )
-            elif isinstance(option, dict):
-                processed_dict = {}
-                for key, value in option.items():
-                    processed_dict[key] = process_options(value)
-                return processed_dict
-            elif isinstance(option, list):
-                processed_list = []
-                for item in option:
-                    processed_list.append(process_options(item))
-                return processed_list
-            else:
-                return option
-
-        self.options = process_options(self.options)
+                self.options[option] = value
 
         if self.Options:
             try:

cumulusci/core/tests/test_tasks.py

@@ -105,22 +105,6 @@ def test_init_options__project_config_substitution(self):
         task = BaseTask(self.project_config, self.task_config, self.org_config)
         assert task.options["test_option"] == "baz"
 
-    # For variable substitution in nested structures
-    def test_init_options__project_config_substitution_nested(self):
-        self.project_config.config["foo"] = {"bar": "baz", "fighters": "pretender"}
-        self.project_config.config["vulf"] = {"peck": "DeanTown"}
-        self.task_config.config["options"] = {
-            "test_option": "$project_config.foo__bar",
-            "songs": [
-                {"foo_fighters": "$project_config.foo__fighters"},
-                {"vulfpeck": "$project_config.vulf__peck"},
-            ],
-        }
-        task = BaseTask(self.project_config, self.task_config, self.org_config)
-        assert task.options["test_option"] == "baz"
-        assert task.options["songs"][0]["foo_fighters"] == "pretender"
-        assert task.options["songs"][1]["vulfpeck"] == "DeanTown"
-
     def test_init_options__not_shared(self):
         self.project_config.config["foo"] = {"bar": "baz"}
         self.task_config.config["options"] = {}