run e2e test on merge

[gtrrz-victor]

No description provided.

[cursor]

PR Summary

Low Risk
Small CI trigger change limited to when the workflow runs; no product code or security logic is modified.

Overview
The E2E Tests GitHub Actions workflow is now triggered on pushes to main in addition to manual workflow_dispatch, enabling E2E runs automatically after merges.

Concurrency behavior is unchanged (still cancels in-progress runs within the e2e-tests group).

^{Written by Cursor Bugbot for commit dd67e87. Configure here.}

[Copilot]

Pull request overview

This PR enables automatic execution of E2E tests when code is merged to the main branch. Previously, E2E tests could only be triggered manually via workflow_dispatch. This change aligns the E2E workflow with the existing CI and lint workflows, which already run automatically on pushes to main.

Changes:

• Add push trigger to E2E workflow for the main branch