Update e2e tests workflow to trigger on merge commits

[cesarcosta99]

Description

Currently, we run e2e tests on every pull request. To optimize our test strategy and reduce redundant executions (QIT custom e2e tests are running too), we should adjust our GitHub workflow to run local e2e tests only on merge commits instead. This will ensure that tests run in a stable and controlled environment while reducing unnecessary load on CI.

Acceptance criteria

• Local e2e tests should trigger on merges to develop and trunk instead of every pull request.

References

For more context see pc4etw-1oD-p2.