Backend: Wrong parent pipeline status when child pipeline contains optional manual jobs
### Summary
When a child pipeline contains only optional (`allow_failure: true`) manual jobs, which were not run yet, the status of the parent pipeline is set to `failed` even though no jobs have failed.
### Steps to reproduce
1. Create parent pipeline `.gitlab-ci.yml`:
```yaml
stages:
- trigger_pipeline
trigger_pipeline:
stage: trigger_pipeline
trigger:
include:
- local: .gitlab-ci-include.yml
strategy: depend
```
2. Create child pipeline `.gitlab-ci-include.yml`:
```yaml
stages:
- test
test:
stage: test
allow_failure: true
script:
- echo 1
rules:
- when: manual
```
### Example Project
https://gitlab.com/sandra17/gitlab-ci-wrong-pipeline-status/
### What is the current *bug* behavior?
The status of the parent pipeline is set to `failed`.
### What is the expected *correct* behavior?
The status of the pipeline should be set to `passed` if no jobs have failed.
### Acceptance criteria
* Test with `trigger:strategy:depend` and without.
issue