use python 3.9.18 instead of 3.9.15
To upgrade on Ubuntu and pyenv, I had to do the following:

```
sudo apt install zlib1g zlib1g-dev libssl-dev libbz2-dev libsqlite3-dev
libncurses-dev libffi-dev liblzma-dev libreadline-dev graphviz
libgraphviz-dev
pyenv update
pyenv install 3.9.18
```

and in every project folder

```
poetry env use 3.9.18
poetry update python
```
use python 3.9.18 instead of 3.9.15: To upgrade on Ubuntu and pyenv, I had to do the following:

```
sudo apt install zlib1g zlib1g-dev libssl-dev libbz2-dev libsqlite3-dev
libncurses-dev libffi-dev liblzma-dev libreadline-dev graphviz
libgraphviz-dev
pyenv update
pyenv install 3.9.18
```

and in every project folder

```
poetry env use 3.9.18
poetry update python
```