Utilize developers' muscle memory to incentivize using the pytest runner
instead of the legacy one. The script also serves as basic examples of
how to run the pyest command to achieve the same results as the legacy
runner.
Invoking pytest directly should be the end goal, since it offers many
potentially useful options (refer to pytest --help).
(cherry picked from commit 4dbe8e5347)
(also manually added a additional run.sh -> legacy.run.sh renames)
ac1e7eb40d