Fix ONVIF camera connection issues by disabling aiohttp auto-decompression

[bdraco]

Summary

This PR fixes connection issues with ONVIF cameras (particularly those using Thingino firmware) that were introduced in v4.0.3. The previous fix for double gzip decompression (#135) caused compatibility issues with certain cameras.

Problem

The previous approach filtered out the Content-Encoding header after aiohttp automatically decompressed responses. This caused issues with cameras that:

• Send uncompressed responses despite Content-Encoding headers
• Have non-standard compression implementations
• Expect the Content-Encoding header to be preserved

Solution

Instead of filtering headers after aiohttp processes the response, this PR:

1. Disables automatic decompression in aiohttp by adding auto_decompress=False to all requests
2. Preserves all headers including Content-Encoding
3. Lets zeep handle decompression based on the Content-Encoding header

Changes

• Added auto_decompress=False parameter to session.post() and session.get() calls
• Removed the _filter_headers() method that was stripping Content-Encoding headers
• Updated tests to reflect the new behavior where Content-Encoding is preserved

Testing

• All existing tests pass
• Updated gzip-related tests to verify Content-Encoding header is preserved
• Tested with both compressed and uncompressed responses

Related Issues

• Fixes ONVIF don’t work after 2025.8.2 update with Xiaomi 2K camera using custom Thingino firmware home-assistant/core#150735
• Addresses regression from Fix double gzip decompression error in aiohttp transport #135

Impact

This change ensures compatibility with all ONVIF cameras while still preventing double decompression issues. The responsibility for decompression is now properly delegated to zeep, which can handle it correctly based on the actual Content-Encoding header.

[codecov]

Codecov Report

✅ All modified and coverable lines are covered by tests.

Files with missing lines	Coverage Δ
onvif/zeep_aiohttp.py	96.51% <100.00%> (-0.12%)	⬇️

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