[3.13] gh-109413: Enable `strict_optional = true` for `libregrtest/run_workers` (GH-126855) (#126967)

gh-109413: Enable `strict_optional = true` for `libregrtest/run_workers` (GH-126855)
(cherry picked from commit a1d9c8aa800dd7c9eb634f89646be10e9cfc9c8d)

Co-authored-by: sobolevn <[email protected]>
Co-authored-by: Alex Waygood <[email protected]>
2 files changed