fix(core): Make node execution order configurable, and backward-compatible (#6507)

* fix(core): Make node execution order configurable, and backward-compatible

* ⚡ Also add new Merge-Node behaviour

* ⚡ Fix typo

* Fix lint issue

* update labels

* rename legacy to v0

* remove the unnecessary log

* default all new workflows to use v1 execution-order

* remove the controller changes

* clone default settings to avoid it getting modified

---------

Co-authored-by: Jan Oberhauser <jan.oberhauser@gmail.com>

packages/workflow/src/Workflow.ts

@@ -1191,26 +1191,14 @@ export class Workflow {
 				connectionInputData = inputData.main[0] as INodeExecutionData[];
 			}
 
-			let forceInputNodeExecution = nodeType.description.forceInputNodeExecution;
-			if (forceInputNodeExecution !== undefined) {
-				if (typeof forceInputNodeExecution === 'string') {
-					forceInputNodeExecution = !!this.expression.getSimpleParameterValue(
-						node,
-						forceInputNodeExecution,
-						mode,
-						additionalData.timezone,
-						{ $version: node.typeVersion },
-					);
-				}
-
-				if (!forceInputNodeExecution) {
-					// If the nodes do not get force executed data of some inputs may be missing
-					// for that reason do we use the data of the first one that contains any
-					for (const mainData of inputData.main) {
-						if (mainData?.length) {
-							connectionInputData = mainData;
-							break;
-						}
+			const forceInputNodeExecution = this.settings.executionOrder !== 'v1';
+			if (!forceInputNodeExecution) {
+				// If the nodes do not get force executed data of some inputs may be missing
+				// for that reason do we use the data of the first one that contains any
+				for (const mainData of inputData.main) {
+					if (mainData?.length) {
+						connectionInputData = mainData;
+						break;
 					}
 				}
 			}