This patch fixes three issues:
1. It changes the condition for workflows so they can be run not
only from the Tarantool repository but from any repository in the
Tarantool organization.

2. Reusable workflows substitute the `${{ github.workflow }}`
context variable with the name of their top-level workflow. This
behavior causes concurrency group clashes when several reusable
workflows are called from a single top-level workflow. This patch
adds an additional constant part to the concurrency group pattern
to solve the issue.

3. The checkout actions use the reference from the repository in
which the top-level workflow is located instead of the one where
the reusable workflow is located. This patch solves the issue by
passing the reference explicitly.

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