Project Access Token (bot user) is unable to trigger multi-project pipeline
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### Proposal and explanation
Create two test projects, name them **alpha** and **beta**, make both of them private.
Create the following job definition in project **alpha**:
```
downstream-pipeline:
trigger:
include:
- project: 'beta'
ref: 'master'
file: '.gitlab-ci.yml'
```
Create project access token (PAT) in **alpha** (and hence the bot user will be created). Push to **alpha** using this token. That triggers the pipeline in **alpha**, as expected. However, the pipeline will fail with the following error:
`Project beta not found or access denied!`
Obviously, bot user (triggerer in this case) has no access to **beta**. Additionally, [a bot user cannot be added to any other project](https://docs.gitlab.com/ee/user/project/settings/project_access_tokens.html#project-bot-users) so the issue cannot be resolved that way.
Ideally, users should have a way to trigger pipelines like this with bot users (project access tokens).
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issue