fix(Gmail Node): Do not break threads while creating drafts (#16272)

Co-authored-by: Shireen Missi <94372015+ShireenMissi@users.noreply.github.com>
Co-authored-by: cubic-dev-ai[bot] <191113872+cubic-dev-ai[bot]@users.noreply.github.com>

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

@@ -193,6 +193,15 @@ describe('Test Gmail Node v2', () => {
 				.query({ userId: 'me', uploadType: 'media' })
 				.reply(200, messages[0]);
 			gmailNock.delete('/v1/users/me/drafts/test-draft-id').reply(200, messages[0]);
+			gmailNock
+				.get('/v1/users/me/threads/test-thread-id')
+				.query({
+					format: 'metadata',
+					metadataHeaders: 'Message-ID',
+				})
+				.reply(200, {
+					messages: [{ payload: { headers: ['jjkjkjkf@reply.com'] } }],
+				});
 			gmailNock
 				.get('/v1/users/me/drafts/test-draft-id')
 				.query({ format: 'raw' })