Dmypy ignoring aditional section names on config file

Bug Report

Running dmypy as

python -m mypy.dmypy --status-file '...' run  -- src/ --show-column-numbers --no-error-summary --no-pretty --no-color-output --config-file mypy.ini --python-executable

with a mypy.ini with the following config:

[mypy]
files = sales_register/
python_version = 3.9
ignore_missing_imports = True
follow_imports = skip
plugins = pydantic.mypy
local_partial_types = False


[mypy-adapters.repositories.postgres.migrations.*]
ignore_errors = True

are not ignoring errors in src/adapters/repositories/postgres/migrations/ files. Running just mypy --config-file=mypy.ini works fine.

To Reproduce

1. Create a src folder, and a src/a folder inside
2. Create a test.py file inside src/a with the following code:

def a(x: str) -> str:
    return x

b: int = a('1') # Obviously mypy should raise something here

3. Create a mypy.ini file with ignore_errors=True in [mypy-a.*] to skip error in the src/a/test.py file
4. Runs python -m mypy.dmypy --status-file '...' run -- src/ --show-column-numbers --no-error-summary --no-pretty --no-color-output --config-file mypy.ini --python-executable

Expected Behavior

Shouldnt raise any error

Actual Behavior

Raising TypeError

Your Environment

• Mypy version used: 0.812
• Python version used: 3.9
• Operating system and version: macOS 11.3.1

Start by reproducing the issue with python -m mypy.dmypy, the shown mypy.ini, and the src/a/test.py example, then compare it with mypy --config-file=mypy.ini. Trace how the dmypy entry point handles additional config sections; done means the [mypy-a.*] setting suppresses the reported error.