ci: drop useless fail-fast clause

AFAIU it only has meaning for jobs constructed with matrix expansion.
See the documentation: [1].

It is relevant to [2] as well, but already fixed on nektos/act side.

[1]: https://docs.github.com/en/actions/learn-github-actions/workflow-syntax-for-github-actions#jobsjob_idstrategyfail-fast
[2]: https://github.com/tarantool/tarantool-qa/issues/118

(cherry picked from commit 474d1cc2)