Cannot use pyproject.toml configs on the first run

[0xDEC0DE]

There is a small bootstrapping problem with the pyproject.toml support.

Steps to reproduce

• Install stestr 4.1.0
• Add configs to pyproject.toml
• rm -rf .stestr .stestr.conf
• stestr run

Expected result

It runs the defined tests

Actual behavior

No config file found and --test-path not specified. Either create or specify a .stestr.conf or use --test-path 

Workaround

Providing a --test-path switch for the first run will allow the pyproject.toml to be used for all runs thereafter.

It is also possible to "fake it" and create a repo directory by hand:

mkdir .stestr
echo 0 > .stestr/next-stream
echo 1 > .stestr/format

Miscellany

This appears to be due to some extra bootstrapping code in the run workflow that was overlooked, and not under test.