fix(core): Typing in version (#701)

Supports:
https://github.com/testcontainers/testcontainers-python/issues/305
Related :
https://github.com/testcontainers/testcontainers-python/pull/691
https://github.com/testcontainers/testcontainers-python/pull/692 #700

```
poetry run mypy --config-file pyproject.toml core/testcontainers/core/version.py 
Success: no issues found in 1 source file
```

Old
```
                    Error Summary                     
┏━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━┳━━━━━━━━┓
┃ File Path                                 ┃ Errors ┃
┡━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━╇━━━━━━━━┩
│ core/testcontainers/core/version.py       │ 12     │
│ core/testcontainers/core/docker_client.py │ 14     │
│ core/testcontainers/core/image.py         │ 17     │
│ core/testcontainers/core/waiting_utils.py │ 8      │
│ core/testcontainers/core/container.py     │ 20     │
│ core/tests/test_new_docker_api.py         │ 4      │
│ core/tests/test_docker_in_docker.py       │ 2      │
│ core/testcontainers/compose/compose.py    │ 22     │
│ core/testcontainers/compose/__init__.py   │ 2      │
│ core/tests/test_version.py                │ 2      │
│ core/tests/test_ryuk.py                   │ 2      │
│ core/tests/test_registry.py               │ 1      │
│ core/tests/test_image.py                  │ 3      │
│ core/tests/test_compose.py                │ 7      │
└───────────────────────────────────────────┴────────┘
Found 116 errors in 14 files.
```
New
```
                    Error Summary                     
┏━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━┳━━━━━━━━┓
┃ File Path                                 ┃ Errors ┃
┡━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━╇━━━━━━━━┩
│ core/testcontainers/core/docker_client.py │ 14     │
│ core/testcontainers/core/image.py         │ 17     │
│ core/testcontainers/core/waiting_utils.py │ 8      │
│ core/testcontainers/core/container.py     │ 20     │
│ core/tests/test_new_docker_api.py         │ 4      │
│ core/tests/test_docker_in_docker.py       │ 2      │
│ core/testcontainers/compose/compose.py    │ 22     │
│ core/testcontainers/compose/__init__.py   │ 2      │
│ core/tests/test_ryuk.py                   │ 2      │
│ core/tests/test_registry.py               │ 1      │
│ core/tests/test_image.py                  │ 3      │
│ core/tests/test_compose.py                │ 7      │
└───────────────────────────────────────────┴────────┘
Found 102 errors in 12 files.
```