[dist] add pyproject.toml

While build only installs setuptools and weel to isolated environment
but packaging is needed by setup.py. add pyproject.toml file to
determine requirements for build-system.

Remove flake8-executable due to false possitives.

Bug: T355988
Change-Id: Ib241d68109d87cc0924994729922c222ce0888e9
---
A pyproject.toml
1 file changed, 18 insertions(+), 0 deletions(-)

diff --git a/pyproject.toml b/pyproject.toml
new file mode 100644
index 0000000..e94bba3
--- /dev/null
+++ b/pyproject.toml
@@ -0,0 +1,2 @@
+[build-system]
+requires = ["packaging", "setuptools", "wheel"]
\ No newline at end of file

