fix: Enable mypy in the CI (#842)

1. leftovers from a previous mypy refactor
```python
core/testcontainers/core/config.py:42: error: Redundant cast to "str"  [redundant-cast]
            socket_path = cast("str", socket_path)
 ```
 
 Post fix:
 ```bash
#poetry run mypy --config-file pyproject.toml core
Success: no issues found in 36 source files
```

2. add mypy check to the CI under lint, also create a simple report if
something is wrong.

Author: Tranquility2

.github/workflows/ci-lint.yml

@@ -20,9 +20,14 @@ jobs:
       - name: Install Python dependencies
         run: poetry install --no-interaction
       - name: Execute pre-commit handler
+        continue-on-error: true
         run: |
           poetry run pre-commit run check-toml
           poetry run pre-commit run trailing-whitespace
           poetry run pre-commit run end-of-file-fixer
           poetry run pre-commit run ruff
           poetry run pre-commit run ruff-format
+      - name: Execute mypy
+        run: |
+          make mypy-core-report
+          make mypy-core

Makefile

@@ -31,7 +31,10 @@ coverage:  ## Target to combine and report coverage.
 lint:  ## Lint all files in the project, which we also run in pre-commit
 	poetry run pre-commit run -a
 
-mypy-core-report:
+mypy-core:  ## Run mypy on the core package
+	poetry run mypy --config-file pyproject.toml core
+
+mypy-core-report:  ## Generate a report for mypy on the core package
 	poetry run mypy --config-file pyproject.toml core | poetry run python scripts/mypy_report.py
 
 docs: ## Build the docs for the project

core/testcontainers/core/config.py

@@ -7,7 +7,7 @@
 from os import environ
 from os.path import exists
 from pathlib import Path
-from typing import Final, Optional, Union, cast
+from typing import Final, Optional, Union
 
 import docker
 
@@ -39,7 +39,6 @@ def get_docker_socket() -> str:
     try:
         client = docker.from_env()
         socket_path = client.api.get_adapter(client.api.base_url).socket_path
-        socket_path = cast("str", socket_path)
         # return the normalized path as string
         return str(Path(socket_path).absolute())
     except Exception: