refactor: restore AttributeRemovedError for resp.body

[vytas7]

The blocked resp.body property was introduced in #2090, and then removed later in the 4.0( cycle by oversight.

It is useful to have it, since otherwise setting resp.body in legacy code silently does nothing, and it is hard to understand what is going on.

Example when using swagger-ui-py (unfortunately, it needs to be updated):

2024-10-09 13:44:20 [FALCON] [ERROR] GET /api/doc => Traceback (most recent call last):
  File "<venv>/lib/python3.8/site-packages/falcon/app.py", line 440, in __call__
    responder(req, resp, **params)
  File "<venv>/lib/python3.8/site-packages/swagger_ui/handlers/falcon.py", line 19, in on_get
    resp.body = doc.doc_html
  File "<venv>/lib/python3.8/site-packages/falcon/response.py", line 221, in body
    raise AttributeRemovedError(
falcon.util.deprecation.AttributeRemovedError: The body attribute is no longer supported. Please use the text attribute instead.

(With 4.0.0b1, the page is completely blank, and nothing is logged on the server side either.)

[codecov]

Codecov Report

All modified and coverable lines are covered by tests ✅

Project coverage is 100.00%. Comparing base (25027b2) to head (35b4af7).
Report is 1 commits behind head on master.

Additional details and impacted files

@@            Coverage Diff             @@
##            master     #2361    +/-   ##
==========================================
  Coverage   100.00%   100.00%            
==========================================
  Files           64        64            
  Lines         7721      7727     +6     
  Branches      1269      1073   -196     
==========================================
+ Hits          7721      7727     +6     

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[CaselIT]

So this wasn't in 3.x?

[vytas7]

The attribute was already deprecated in 3.x, but resp.body raising AttributeRemovedError has never been part of a stable release.

[vytas7]

I am going to disable the Firefox gate for now. I haven't found the reason yet, but I suspect something is not working correctly with geckodriver on Linux and the newest Firefox 131.0. I won't have the bandwidth to dig into this.

Locally, it works for me, but I cannot make the browser headless anymore, it always pops up. In the gate, 1/2 tests fail.