[GitHub Actions] - Added documentation in ACTIONS.md

[dannymartinm]

As part of the issue 21106, @elink21 and I have implemented the self-hosted runners for the Ubuntu and Windows operating systems.

Please see the Approved Pull Request (PR#22703) for reference.

In this PR you will find the following changes:

• Added detailed information in ACTIONS.md file regarding how the workflows need to be implemented in order to runs-on self-hosted runners.

PR#16511 : Previous PR for reference.
BEAM-12812: Original Jira may contain additional context.

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