Modal

* Added deprecation warnings when using Python 3.8 locally or in a container. Python 3.8 is nearing EOL, and Modal will be dropping support for it soon.

* Deprecated the `Image.conda` constructor and the `Image.conda_install` / `Image.conda_update_from_environment` methods. Conda-based images had a number of tricky issues and were generally slower and heavier than images based on `micromamba`, which offers a similar featureset and can install packages from the same repositories.
* Added the `spec_file` parameter to allow `Image.micromamba_install` to install dependencies from a local file. Note that `micromamba` supports conda yaml syntax along with simple text files.

* Added a deprecation warning when object names are invalid. This applies to `Dict`, `NetworkFileSystem`, `Secret`, `Queue`, and `Volume` objects. Names must be shorter than 64 characters and may contain only alphanumeric characters, dashes, periods, and underscores. These rules were previously enforced, but the check had inadvertently been dropped in a recent refactor. Please update the names of your objects and transfer any data to retain access, as invalid names will become an error in a future release.

- Added a command-line interface for interacting with `modal.Queue` objects. Run `modal queue --help` in your terminal to see what is available.

* Added a command-line interface for interacting with `modal.Dict` objects. Run `modal dict --help` in your terminal to see what is available.

* `Secret.from_dotenv` now accepts an optional filename keyword argument:

python
app.function(secrets=[modal.Secret.from_dotenv(filename=".env-dev")])
def run():
...