bug: asdf plugin test nodejs . 'node --version' unexpectedly only operates on commited code

### Describe the Bug

Documentation says I can test the local plugin:

```
You also have the option to pass a relative path to plugin-test.

For example, if the test script is ran in the repo directory: asdf plugin test nodejs . 'node --version'.
```
https://asdf-vm.com/plugins/create.html#testing-plugins

But when I run this I don't see behaviour that is reflected in my uncommited changes.

### Steps to Reproduce

1. clone any plugin locally
2. make some changes, (the download message is a good start)
3. do not commit changes
4. run `asdf plugin test THEPLUGINNAME . 'somethingsomethingsomething darkside'`
5. witness the absence of your glory 🎺☁️🌥️🌤️💀

### Expected Behaviour

I expect to see how awesome I am

🎺☁️🌥️🌤️👼🏻

### Actual Behaviour

I'm dissapointed.

### Environment

```shell
> asdf info
OS:
Linux brass 6.1.11-200.fc37.x86_64 #1 SMP PREEMPT_DYNAMIC Thu Feb 9 19:20:24 UTC 2023 x86_64 x86_64 x86_64 GNU/Linux

SHELL:
zsh 5.9 (x86_64-redhat-linux-gnu)

ASDF VERSION:
v0.11.2-8eb11b8

ASDF ENVIRONMENT VARIABLES:
ASDF_DIR=/home/zenobius/.asdf

ASDF INSTALLED PLUGINS:
act https://github.com/grimoh/asdf-act.git master 8c5f499
awscli https://github.com/MetricMike/asdf-awscli.git main c645552
aws-copilot https://github.com/NeoHsu/asdf-copilot main 1341900
fzf https://github.com/kompiro/asdf-fzf.git master d19eb67
github-cli https://github.com/bartlomiejdanek/asdf-github-cli.git master 9e0a9d7
golang https://github.com/kennyp/asdf-golang.git master f006a12
java https://github.com/halcyon/asdf-java.git master 6598845
neovim https://github.com/richin13/asdf-neovim.git master 15e9a80
nodejs https://github.com/asdf-vm/asdf-nodejs.git master c9e5df4
pnpm https://github.com/jonathanmorley/asdf-pnpm.git master 95752a9
python https://github.com/danhper/asdf-python.git master 8505457
shellcheck https://github.com/luizm/asdf-shellcheck.git master 0f79f0b
shfmt https://github.com/luizm/asdf-shfmt.git master a42c5ff
yarn https://github.com/twuni/asdf-yarn.git main 376c540
```
```

### asdf plugins affected (if relevant)

any plugin.

Start at the `asdf plugin test` entry point and reproduce the documented command with an uncommitted plugin change. Trace how the relative plugin path is used, then verify that the command reflects local changes rather than only committed code.

Written by the indexing model from the issue text.