Poetry ignores no-binary options and downloads .whl files

• Poetry version: 1.6.1
• Python version: 3.8
• OS version and name: Red Hat Enterprise Linux Server 7.9 (Maipo)
• pyproject.toml: https://gist.github.com/HydraCro/2da652bbb270805e584ff1104a127edc

• I am on the latest stable Poetry version, installed using a recommended method.
• I have searched the issues of this repo and believe that this is not a duplicate.
• I have consulted the FAQ and blog for any relevant entries or release notes.
• If an exception occurs when executing a command, I executed it again in debug mode (-vvv option) and have included the output below.

Issue

I am running poetry installation with no-binary option.
Due to company security policies only source code dependencies are allowed, meaning no .whl files.
However I have tried using both:

• poetry config --local installer.no-binary :all: (local and global)
• export POETRY_INSTALLER_NO_BINARY=:all:
  In both cases poetry installation still downloads .whl files, this is the log:

Source (PyPI): Downloading: https://files.pythonhosted.org/packages/7b/9b/d4f61d21bf2c9a653d02bf5ef8910c03e0cbc876db5eebae358421261b4c/responses-0.14.0-py2.py3-none-any.whl
Creating new session for files.pythonhosted.org
[urllib3.connectionpool] Starting new HTTPS connection (1): files.pythonhosted.org:443
[urllib3.connectionpool] https://files.pythonhosted.org:443 "GET /packages/7b/9b/d4f61d21bf2c9a653d02bf5ef8910c03e0cbc876db5eebae358421261b4c/responses-0.14.0-py2.py3-none-any.whl HTTP/1.1" 200 27408
   1: fact: responses (0.14.0) depends on requests (>=2.0)
   1: fact: responses (0.14.0) depends on urllib3 (>=1.25.10)
   1: fact: responses (0.14.0) depends on six (*)
   1: selecting responses (0.14.0)
   1: derived: six

Reproduce with Poetry 1.6.1 and Python 3.8 using the linked pyproject.toml, checking both installer.no-binary :all: and POETRY_INSTALLER_NO_BINARY. Trace installation of the responses dependency and verify whether a source archive is selected instead of a .whl file. Done means both configuration forms enforce source-only installation.