• I am on the latest Poetry version.

• I have searched the issues of this repo and believe that this is not a duplicate.

• If an exception occurs when executing a command, I executed it again in debug mode (-vvv option).

• OS version and name: elementary OS 5.1 Hera

• Poetry version: 1.1.0b2

• Link of a Gist with the contents of your pyproject.toml file: https://gist.github.com/MrGreenTea/992a1795471c00d727c02920d4288f16

Issue

When updating my packages version with poetry version old dist-info directories are left in site-packages.
This trips up pip, importlib and pkg_resources for example when trying to find the packages information.
To reproduce:
(run with poetry config virtualenvs.in-project true)

1. ❯ poetry new example
2. ❯ poetry install
3. ❯ ls .venv/lib/python3.8/site-packages/example*.dist-info

.venv/lib/python3.8/site-packages/example-0.1.0.dist-info:
INSTALLER  METADATA  RECORD

4. ❯ poetry version minor && poetry install
5. ❯ ls .venv/lib/python3.8/site-packages/example*.dist-info

.venv/lib/python3.8/site-packages/example-0.1.0.dist-info:
INSTALLER  METADATA  RECORD

.venv/lib/python3.8/site-packages/example-0.2.0.dist-info:
INSTALLER  METADATA  RECORD

6. ❯ poetry run pip show example

Name: example
Version: 0.2.0
Summary: 
Home-page: None
Author: Jonas Bulik
Author-email: [email protected]
License: None
Location: /tmp/example/.venv/lib/python3.8/site-packages
Requires: 
Required-by: 

7. ❯ poetry version 0.1.0
8. ❯ poetry run pip show example

Name: example
Version: 0.2.0
Summary: 
Home-page: None
Author: Jonas Bulik
Author-email: [email protected]
License: None
Location: /tmp/example/.venv/lib/python3.8/site-packages
Requires: 
Required-by: