secrets_dir configuration setting raises an error when the directory doesn't exist

[Midnighter]

Checks

• I added a descriptive title to this issue
• I have searched (google, github) for similar issues and couldn't find anything
• I have read and followed the docs and still think this is a bug

Bug

Output of python -c "import pydantic.utils; print(pydantic.utils.version_info())":

             pydantic version: 1.7.3
            pydantic compiled: True
                 install path: ~/.pyenv/versions/3.8.5/envs/fetcher/lib/python3.8/site-packages/pydantic
               python version: 3.8.5 (default, Sep  4 2020, 14:39:18)  [GCC 9.3.0]
                     platform: Linux-5.8.0-7630-generic-x86_64-with-glibc2.29
     optional deps. installed: ['typing-extensions', 'devtools']

I have declared a settings model that can read values from the environment, a .env file, or from Docker secrets as follows.

import pydantic

class Settings(BaseSettings):

    password: SecretStr = Field(..., env="APP_PASSWORD")

    class Config:
        """Configure settings values discovery locations."""

        env_file = ".env"
        secrets_dir = "/run/secrets"

As per the documentation, checking for a value from a secret is the fourth attempt pydantic makes. However, when I just work in my development environment where the directory /run/secrets doesn't exist, instantiating the model raises an error.

pydantic.env_settings.SettingsError: directory "/run/secrets" does not exist

This is annoying because it happens even though I have the values in a .env file. Thus I have to circumvent this by using Settings(_secrets_dir=".") which would mean that I need a special case for my dev environment. I think, when values are provided to the instance, or from the environment, or from .env first, it shouldn't matter whether the secrets_dir exists or not.