ci: Introduce no-plain-errors lint rule for BE packages (no-changelog) (#7961)

## Summary
Require `ApplicationError` or its child classes instead of plain `Error`
in BE packages. This ensures the error will be normalized when reported
to Sentry, if applicable.

Follow-up to:
https://github.com/n8n-io/n8n/pulls?q=is%3Apr+is%3Aclosed+applicationerror

...

#### How to test the change:
1. ...


## Issues fixed
Include links to Github issue or Community forum post or **Linear
ticket**:
> Important in order to close automatically and provide context to
reviewers

...


## Review / Merge checklist
- [ ] PR title and summary are descriptive. **Remember, the title
automatically goes into the changelog. Use `(no-changelog)` otherwise.**
([conventions](https://github.com/n8n-io/n8n/blob/master/.github/pull_request_title_conventions.md))
- [ ] [Docs updated](https://github.com/n8n-io/n8n-docs) or follow-up
ticket created.
- [ ] Tests included.
> A bug is not considered fixed, unless a test is added to prevent it
from happening again. A feature is not complete without tests.
  >
> *(internal)* You can use Slack commands to trigger [e2e
tests](https://www.notion.so/n8n/How-to-use-Test-Instances-d65f49dfc51f441ea44367fb6f67eb0a?pvs=4#a39f9e5ba64a48b58a71d81c837e8227)
or [deploy test
instance](https://www.notion.so/n8n/How-to-use-Test-Instances-d65f49dfc51f441ea44367fb6f67eb0a?pvs=4#f6a177d32bde4b57ae2da0b8e454bfce)
or [deploy early access version on
Cloud](https://www.notion.so/n8n/Cloudbot-3dbe779836004972b7057bc989526998?pvs=4#fef2d36ab02247e1a0f65a74f6fb534e).

packages/@n8n_io/eslint-config/local-rules.js

@@ -353,6 +353,49 @@ module.exports = {
 			};
 		},
 	},
+
+	'no-plain-errors': {
+		meta: {
+			type: 'problem',
+			docs: {
+				description:
+					'Only `ApplicationError` (from the `workflow` package) or its child classes must be thrown. This ensures the error will be normalized when reported to Sentry, if applicable.',
+				recommended: 'error',
+			},
+			messages: {
+				useApplicationError:
+					'Throw an `ApplicationError` (from the `workflow` package) or its child classes.',
+			},
+			fixable: 'code',
+		},
+		create(context) {
+			return {
+				ThrowStatement(node) {
+					if (!node.argument) return;
+
+					const isNewError =
+						node.argument.type === 'NewExpression' && node.argument.callee.name === 'Error';
+
+					const isNewlessError =
+						node.argument.type === 'CallExpression' && node.argument.callee.name === 'Error';
+
+					if (isNewError || isNewlessError) {
+						return context.report({
+							messageId: 'useApplicationError',
+							node,
+							fix: (fixer) =>
+								fixer.replaceText(
+									node,
+									`throw new ApplicationError(${node.argument.arguments
+										.map((arg) => arg.raw)
+										.join(', ')})`,
+								),
+						});
+					}
+				},
+			};
+		},
+	},
 };
 
 const isJsonParseCall = (node) =>