Document disabling E704 (#3888)

Linking #3887

.flake8

@@ -1,6 +1,6 @@
 [flake8]
 # B905 should be enabled when we drop support for 3.9
-ignore = E203, E266, E501, W503, B905, B907
+ignore = E203, E266, E501, E704, W503, B905, B907
 # line length is intentionally set to 80 here because black uses Bugbear
 # See https://black.readthedocs.io/en/stable/the_black_code_style/current_style.html#line-length for more details
 max-line-length = 80

docs/guides/using_black_with_other_tools.md

@@ -173,7 +173,7 @@ limit of `88`, _Black_'s default. This explains `max-line-length = 88`.
 ```ini
 [flake8]
 max-line-length = 88
-extend-ignore = E203
+extend-ignore = E203, E704
 ```
 
 </details>

docs/the_black_code_style/current_style.md

@@ -173,7 +173,7 @@ If you use Flake8, you have a few options:
    max-line-length = 80
    ...
    select = C,E,F,W,B,B950
-   extend-ignore = E203, E501
+   extend-ignore = E203, E501, E704
    ```
 
    The rationale for E950 is explained in
@@ -184,7 +184,7 @@ If you use Flake8, you have a few options:
    ```ini
    [flake8]
    max-line-length = 88
-   extend-ignore = E203
+   extend-ignore = E203, E704
    ```
 
 An explanation of why E203 is disabled can be found in the [Slices section](#slices) of