Inline config 'disable-error-code = attr-defined' does not disable errors #11462

Bug Report

Setting # mypy: disable-error-code = attr-defined within a module does not disable those errors.

To Reproduce

1. Create the example file:

   $ echo "# mypy: disable-error-code = attr-defined
   > class Foo: pass
   > Foo.a" > example.py

   # mypy: disable-error-code = attr=defined
   class Foo: pass
   Foo.a

2. Run mypy example.py

Expected Behavior

mypy should not complain about any errors:

$ mypy example.py
Success: no issues found in 1 source file

Actual Behavior

mypy complains about line 3:

$ mypy example.py
example.py:3: error: "Type[Foo]" has no attribute "a"
Found 1 error in 1 file (checked 1 source file)

Your Environment

• Mypy version used: 0.910
• Mypy command-line flags: None
• Mypy configuration options from mypy.ini (and other config files): None
• Python version used: 3.6.8, 3.8.1
• Operating system and version: Ubuntu 18.04.3 "bionic" running on WSL1 on Windows 10 Pro 20H2

$ pip list
Package           Version
----------------- --------
mypy              0.910
mypy-extensions   0.4.3
pip               21.3.1
setuptools        58.5.2
toml              0.10.2
typed-ast         1.4.3      # for Python 3.6
typing-extensions 3.10.0.2
wheel             0.37.0

Other Notes

1. Running with --disable-error-code attr-defined from the CLI works:

   $ mypy example.py --disable-error-code attr-defined
   Success: no issues found in 1 source file

2. Creating a mypy.ini file in the same directory as example.py and populating it with:

   [mypy]
   disable_error_code = attr-defined
   

   causes the expected behavior (no mypy errors), so it's appears to only be an issue with the inline configuration. Sadly my use case requires me to only ignore these errors on a single file, so using the global mypy.ini config file is not an option.
3. Deleting the .mypy-cache directory does not resolve the issue.
   • Note: If you run other tests (like 1, 2 above), then deleting .mypy-cache is required to get back to a state where the inline-config fails to apply