Added
* `inferred_env_var` to explicitly infer the type, name and default value of an env var.
* `pos_args` to allow for positional arguments in a schema.
* `discard` default value for schema args, which discards an argument from the schema if the value is missing.
* `MatchParser` to return values from discrete matches. This is now the default parser for Mappings and Enums.
* `Optional`s can now be used as parsers
* added official support for python 3.11 and 3.12
Deprecated
* auto-typed env vars are deprecated, use `infer_env_var` instead.
Fixed
* fixed possible race condition when reloading the environment parser, causing multiple reloads.
* significantly improved performance for case-insensitive env var repeat retrieval.
Internal
* use ruff + black for formatting