Dev-cmd

Fix `dev-cmd` handling of execution errors. Previously an uncaught exception assigning
`__traceback__` could be observed in certain situations.

Fix `dev-cmd` for interactive commands that read from stdin.

Fix sdist release to include tests and `uv.lock`.

Add support for Python 3.8.

Also improve color support for Windows.

Add `-q` / `--quiet` to quiet `dev-cmd` output to just the output of the commands it runs.

Also fix the `dev-cmd` exit code to reflect the exit code of a failing command when there is
exactly one failing command.

Finally, fix `dev-cmd` color setting propagation to subprocesses in certain situations where
`NO_COLOR` or `FORCE_COLOR` are present in the environment.

Add knobs to control when and how `dev-cmd` exits an invocation that has command failures:
+ `[tool.dev-cmd] exit-style` and `-k` / `--keep-going` or `-X` / `--exit-style` allow configuring
how quickly the `dev-cmd` invocation exits after a command failure. By default, it exits after the
step containing the 1st command failure completes, but an immediate end or continuation through
all steps can be requested.
+ `[tool.dev-cmd] grace-period` and `--grace-period` allow configuring how in-flight commands are
terminated when exiting an invocation with command errors.