refactor: Use NodeConnectionType consistently across the code base (no-changelog) (#10595)

packages/nodes-base/nodes/Google/Gmail/GmailTrigger.node.ts

@@ -7,6 +7,7 @@ import type {
 	INodeType,
 	INodeTypeDescription,
 } from 'n8n-workflow';
+import { NodeConnectionType } from 'n8n-workflow';
 
 import { DateTime } from 'luxon';
 import {
@@ -52,7 +53,7 @@ export class GmailTrigger implements INodeType {
 		],
 		polling: true,
 		inputs: [],
-		outputs: ['main'],
+		outputs: [NodeConnectionType.Main],
 		properties: [
 			{
 				displayName: 'Authentication',

packages/nodes-base/nodes/Google/Gmail/v1/GmailV1.node.ts

@@ -1,15 +1,16 @@
 /* eslint-disable n8n-nodes-base/node-filename-against-convention */
-import type {
-	IBinaryKeyData,
-	IDataObject,
-	IExecuteFunctions,
-	IHttpRequestMethods,
-	ILoadOptionsFunctions,
-	INodeExecutionData,
-	INodePropertyOptions,
-	INodeType,
-	INodeTypeBaseDescription,
-	INodeTypeDescription,
+import {
+	NodeConnectionType,
+	type IBinaryKeyData,
+	type IDataObject,
+	type IExecuteFunctions,
+	type IHttpRequestMethods,
+	type ILoadOptionsFunctions,
+	type INodeExecutionData,
+	type INodePropertyOptions,
+	type INodeType,
+	type INodeTypeBaseDescription,
+	type INodeTypeDescription,
 } from 'n8n-workflow';
 
 import isEmpty from 'lodash/isEmpty';
@@ -43,8 +44,8 @@ const versionDescription: INodeTypeDescription = {
 	defaults: {
 		name: 'Gmail',
 	},
-	inputs: ['main'],
-	outputs: ['main'],
+	inputs: [NodeConnectionType.Main],
+	outputs: [NodeConnectionType.Main],
 	credentials: [
 		{
 			name: 'googleApi',

packages/nodes-base/nodes/Google/Gmail/v2/GmailV2.node.ts

@@ -9,7 +9,7 @@ import type {
 	INodeTypeBaseDescription,
 	INodeTypeDescription,
 } from 'n8n-workflow';
-import { NodeOperationError } from 'n8n-workflow';
+import { NodeConnectionType, NodeOperationError } from 'n8n-workflow';
 
 import type { IEmail } from '../GenericFunctions';
 import {
@@ -45,8 +45,8 @@ const versionDescription: INodeTypeDescription = {
 	defaults: {
 		name: 'Gmail',
 	},
-	inputs: ['main'],
-	outputs: ['main'],
+	inputs: [NodeConnectionType.Main],
+	outputs: [NodeConnectionType.Main],
 	credentials: [
 		{
 			name: 'googleApi',