fix(deps): replace optional dependencies with dependency groups

Definition: https://packaging.python.org/en/latest/specifications/dependency-groups

The optional dependency table ([project.optional-dependencies]) is
supposed to be user-facing for installs of TagStudio. Meanwhile, the
replacement dependency groups is explicitly meant for extra development
tools, so lets use that.

This does mean the command for a full development environment has changed
from:
```sh
pip install -e '.[dev]'
```

To:
```sh
pip install -e . --group all
```

The documentation has been adjusted for a quick replacement, but
probably should have more information on a later time.

contrib/.envrc-uv

@@ -26,7 +26,7 @@ source "${venv}"/bin/activate
 
 if [ ! -f "${venv}"/pyproject.toml ] || ! diff --brief pyproject.toml "${venv}"/pyproject.toml >/dev/null; then
     printf '%s\n' 'Installing dependencies, pyproject.toml changed...' >&2
-    uv pip install --quiet --editable '.[dev]'
+    uv pip install --quiet --editable . --group all
     cp pyproject.toml "${venv}"/pyproject.toml
 fi