Python-liquid

**Fixes**

- Fixed comparing strings with `<`, `<=`, `>` and `>=` in boolean expressions (`{% if %}` and `{% unless %}`). Previously we were raising a `LiquidTypeError`, now we return the result of comparing two string by their lexicographical order. See [141](https://github.com/jg-rp/liquid/issues/141).

**Features**

- Added `CachingChoiceLoader`, a template loader that chooses between a list of template loaders and caches parsed templates in memory. ([docs](https://jg-rp.github.io/liquid/api/cachingchoiceloader), [source](https://github.com/jg-rp/liquid/blob/main/liquid/builtin/loaders/choice_loader.py#L114))
- Added `PackageLoader`, a template loader that reads templates from Python packages. ([docs](https://jg-rp.github.io/liquid/api/packageloader), [source](https://github.com/jg-rp/liquid/blob/main/liquid/builtin/loaders/package_loader.py))

**Dependencies**

- Python Liquid now depends on [importlib-resources](https://pypi.org/project/importlib-resources/) >= 5.10. This is that backport of [importlib.resources](https://docs.python.org/3/library/importlib.resources.html#importlib.resources.Anchor) from Python's standard library. We use it in `PackageLoader`.

**Fixes**

- Added an additional implementation of the `split` filter, which resolves some compatibility issues between Python Liquid and the reference implementation. Previously, when given an empty string to split or when the string and the delimiter were equal, we used Python's `str.split()` behavior of producing one or two element lists containing empty strings. We now match Shopify/Liquid in returning an empty list for such cases. The new `split` filter will be enabled by default when using [`liquid.future.Environment`](https://jg-rp.github.io/liquid/api/future-environment), and can optionally be registered with `liquid.Environment` for those that don't mind the behavioral change. See [#135](https://github.com/jg-rp/liquid/pull/135).
- Fixed unexpected errors from the `date` filter when it's given an invalid format string. Previously we were raising a `liquid.exceptions.Error` in response to a `ValueError` from [strftime](https://docs.python.org/3/library/datetime.html#datetime.date.strftime). We now raise a `FilterArgumentError` with its `__cause__` set to the `ValueError`.
- Fixed handling of `"%s"` date filter format strings. We now fall back to a string representation of `datetime.timestamp()` for platforms that don't support `%s`. Note that this is for `"%s"` exactly. We don't handle the more general case of `%s` appearing in a longer format string.

Version 1.10.1 was accidentally skipped and not released.

**Features**

- Optionally disable automatic suppression of whitespace only blocks with the `Environment` class attribute `render_whitespace_only_blocks`. ([docs](https://jg-rp.github.io/liquid/guides/whitespace-suppression)).
- All built-in and included "extra" tags now have a `node_class` class attribute specifying the `Node` type the tag contributes to a templates AST. This is done for easier customization through `Tag` and `Node` subclassing.

**Fixes**

- Fixed async loading of templates with the `{% extends %}` tag. Previously templates were being loaded synchronously, even when using `render_async()`. See [124](https://github.com/jg-rp/liquid/issues/124).
- Fixed handling of recursive `{% extends %}` tags during async static analysis. See [125](https://github.com/jg-rp/liquid/issues/125).

**Fixes**

- Removed `is_up_to_date` from `liquid.BoundTemplate.__repr__`. It was causing `RuntimeWarning`s with Python 3.11 when using an async template loader. Specifically warnings about coroutines that were never awaited.
- Fixed the `map` filter. If given a nested array-like input, it now flattens it automatically. See [119](https://github.com/jg-rp/liquid/issues/119).
- Fixed the behavior of the `liquid` tag when other liquid tags appear within it. See [123](https://github.com/jg-rp/liquid/issues/123).

**Features**

- Added the `sum` filter, which will return the sum of all numeric values in its input sequence. ([docs](https://jg-rp.github.io/liquid/language/filters#sum), [source](https://github.com/jg-rp/liquid/blob/14ab1117705db04597d81b613ed6c4a92db10f37/liquid/builtin/filters/array.py#L222)).
- Added `Environment.setup_tags_and_filters()` for easier tag and filter registration when subclassing `Environment`. See [122](https://github.com/jg-rp/liquid/issues/122).