Fix python version to 3.9

[leshikus]

This is a workaround for #332 (it fixes development env; runtime env is still needed)

[Garra1980]

try

• python 3.9.16
  in yml file instead just
• python 3.9

[alexbaden]

Shouldn't we use python 3.9.* or equivalent so we will get security updates, etc without having to manually bump the minor version each time?

[Garra1980]

Shouldn't we use python 3.9.* or equivalent so we will get security updates, etc without having to manually bump the minor version each time?

yes, I think we should try this

[kurapov-peter]

What's the point of setting the version for our dev envs anyway?

[leshikus]

fixed to 3.9.*

[Garra1980]

What's the point of setting the version for our dev envs anyway?

to sync with our benchmarking envs at least