[enh] py: drop deps (#5407)

The difference between decompression with brotli or gzip in HTML files is
negligible for 3 MB of compiled binary package.

Introduced in https://github.com/searxng/searxng/commit/eaa694fb7d0e47b943bc6d6edb6cb6a40ab2d85e

Closes https://github.com/searxng/searxng/security/code-scanning/276
Closes https://github.com/searxng/searxng/security/dependabot/37

searx/engines/bing.py

@@ -201,7 +201,6 @@ def fetch_traits(engine_traits: EngineTraits):
         "User-Agent": gen_useragent(),
         "Accept": "text/html,application/xhtml+xml,application/xml;q=0.9,image/webp,*/*;q=0.8",
         "Accept-Language": "en-US;q=0.5,en;q=0.3",
-        "Accept-Encoding": "gzip, deflate, br",
         "DNT": "1",
         "Connection": "keep-alive",
         "Upgrade-Insecure-Requests": "1",