## What does this PR do?
This PR prepares for removing `httpx`, and reverts back to `requests`.
## Why is this change important?
`httpx` hasn't proven itself to be faster or better than `requests`. On the other
hand it has caused issues on Windows.
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Please update your environment to use requests instead of httpx.
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use
from searx.engines.duckduckgo import _fetch_supported_languages, supported_languages_url # NOQA
so it is possible to easily remove all unused import using autoflake:
autoflake --in-place --recursive --remove-all-unused-imports searx tests