CI: Introduce [octez_monitoring] child release pipeline

What

Depends on !15896 (merged)

This merge request introduces a child pipeline, octez_monitoring, triggered by the release pipelines.

This child pipeline contains:

• The build of Grafazos Dashboards
• The build of the profiling layer1 binaries

Why

The jobs run by the child pipeline are required for some monitoring infrastructes.

This child pipeline ensures that for each release (or release candidate) there will be these monitoring tools associated.

How

• Allow to register child pipelines with inherit rule
• Register octez_monitoring child pipeline.
• Add atrigger job to the octez release pipeline

We include inherit_ rule, so that only the required variables are given to the child pipeline. This prevent some environement variables to be overiden (such as CARGO_NET_OFFLINE) by the parent variables.

Manually testing the MR

See https://gitlab.com/nomadic-labs/tezos/-/pipelines/1577053416

Checklist

• Document the interface of any function added or modified (see the coding guidelines)
• Document any change to the user interface, including configuration parameters (see node configuration)
• Provide automatic testing (see the testing guide).
• For new features and bug fixes, add an item in the appropriate changelog (docs/protocols/alpha.rst for the protocol and the environment, CHANGES.rst at the root of the repository for everything else).
• Select suitable reviewers using the Reviewers field below.
• Select as Assignee the next person who should take action on that MR