submodule recipes should respect `JUST_WORKING_DIR` environment variable and `--working-directory` command line parameter

## issue

submodule recipes do not make use of environment variable `JUST_WORKING_DIRECTORY` (or `--working-directory`) to set their working directory if it is present. they ignore it

## context

from `just --help`:

> -d, --working-directory
Use as working directory. --justfile must also be set [env:
JUST_WORKING_DIRECTORY=.]

and there's this [documented behavior](https://github.com/casey/just/blob/c9ebc97808888394b291763b7dbf61aa83b54842/README.md?plain=1#L3771) for submodules:

> Recipes in submodules without the `[no-cd]` attribute run with the working directory set to the directory containing the submodule source file.

i think submodule recipes should only do that if they're not explicitly told otherwise by `JUST_WORKING_DIRECTORY` or `--working-directory`

## reproduction

### by script

script available in [this gist](https://gist.github.com/sean-xyz/be45862e532035f475a22a2082248b2a)

### step by step

click to expand

1. create a directory for justfiles, not where you're currently at:
```bash
mkdir -p /tmp/some/other/location`
```

2. create `/tmp/some/other/location/justfile`:

```just
mod foo

@pwd:
echo "in justfile:"
echo " \$JUST_WORKING_DIRECTORY: $JUST_WORKING_DIRECTORY"
echo "{{ style("warning") }} \`pwd\`: $(pwd){{ NORMAL }}"
echo "{{ style("warning") }} \$PWD: $PWD{{ NORMAL }}"
```

3. create module `/tmp/some/other/location/foo.just`:

```just
@pwd:
echo "in mod foo:"
echo " \$JUST_WORKING_DIRECTORY: $JUST_WORKING_DIRECTORY"
echo "{{ style("error") }} \`pwd\`: $(pwd){{ NORMAL }}"
echo "{{ style("error") }} \$PWD: $PWD{{ NORMAL }}"
```

4. invoke `justfile` with:

```bash
JUST_WORKING_DIRECTORY="." JUST_JUSTFILE="/tmp/some/other/location/justfile" just pwd
```

note the *warning*-style (yellow) text, showing the _`justfile` respect `JUST_WORKING_DIRECTORY`_

5. invoke submodule `foo.just` with:

```bash
JUST_WORKING_DIRECTORY="." JUST_JUSTFILE="/tmp/some/other/location/justfile" just foo pwd
```

note the *error*-style (red) text, showing the _`submodule` ignore `JUST_WORKING_DIRECTORY`_

## workarounds

* ~add `[no-cd]` to each submodule recipe~
* _this uses invocation directory, rather than `JUST_WORKING_DIRECTORY`_
* use [invocation_directory()](https://github.com/casey/just/tree/c9ebc97808888394b291763b7dbf61aa83b54842?tab=readme-ov-file#invocation-directory) in each submodule recipe
* _not strictly a workaround, as invocation directory != working directory, but they may be the same for many use cases_
* read and use `env('JUST_WORKING_DIRECTORY')` from the recipes themselves, or the submodule file
* _not attempted, but i think it would work_

## related

* [Feature request: setting `[no-cd]` for entire submodule file](https://github.com/casey/just/issues/2754)
* [Shell not found in module](https://github.com/casey/just/issues/2575) and [Improve error message if working-directory does not exist](https://github.com/casey/just/issues/2295) - not directly related, but an issue i hit a few times while trying to find workarounds
`error: Recipe ... could not be run because just could not find the shell: No such file or directory (os error 2)`

Start by running the documented reproduction with JUST_WORKING_DIRECTORY and --working-directory, comparing the top-level recipe with the submodule recipe. Trace the submodule recipe working-directory handling and verify that an explicit working directory takes precedence over the submodule source directory; done means both invocation forms behave consistently while the documented default remains unchanged.

Written by the indexing model from the issue text.