shells/nushell: update to 0.69.1

Today, we're releasing version 0.69 of Nu.

Note: this release is officially 0.69.1 because of a last-minute issue that was
found and fixed.

As part of this release, we also publish a set of optional plugins you can
install and use with Nu.

Themes of this release
Finishing the rework of modules and environment (WindSoilder, kubouch)

If you followed the development since the last release, you might have noticed
we successfully applied "the method of dead ends" pioneered by J叩ra Cimrman

"Somebody had to probe this dead end of human knowledge and announce to the
world: Not this way, friends!"
In short, the source-env experiment did not work out as planned. We hoped to
allow to call source-env with dynamic paths which, however, proved unfeasible.
Therefore, in this release, we remove all notions of source-env from Nushell
and instead use will be used activate the module's environment.
Any call to use will run the module's export-env { ... } block (if there is one)
and keep its environment. A positive side of it is that one call of use is
enough to import both commands/aliases and the environment, there is no need to
call two separate commands as we planned for source-env.

We're also keeping the source command for now, as well as the current config
file format. One reason is that we want to first investigate whether it is
possible to export also regular variables from modules and whether we can use
the module keyword inside modules. However, the use of modules is still
preferred over source as it will become the default way in the future.

Upcoming virtualenv activation changes (kubouch)

To reflect the recent changes to the module environment, we are changing the
virtualenv integration to use overlays. This will come in effect as soon as
this PR

gets merged. In practice, this means that instead of source activate.nu, you'll
use overlay use activate.nu, deactivate will work the same.

Under the hood, calling overlay use activate.nu will activate the activate
overlay and deactivate is just an alias for calling overlay hide activate.
If you wish, you can manually name the overlay, for example overlay use
activate.nu as spam, but then you'd need to remove it with overlay hide spam
instead of deactivate.

Grammar Experiments (JT)

We've recently also started working on some improvements to Nushell's syntax.
While these aren't part of Nushell 0.69, you can try this experimental syntax
in our new grammar

repo. Some experiments we're looking into:

Traditional function definition syntax

def foo(x: int) { ... }

Traditional function call syntax

foo(3)

And much more. We're hoping to talk more about these experiments as they mature.

Breaking changes

We found a regression in the correctness of the -d and -t flags of touch.
To get the release out, we've removed these flags, but hope to replace them
with correct implementations in the future.

We also removed support for duration literals above weeks, including month,
year, and decade literals. These were found to be confusing as it's unclear
what a duration of a month is (30 days? 31 days?)

The str collect command is now str join.

Next Steps

We've been progressing with our design towards 0.80 as outlined in this Notion
page.

Some time was spent trying out possible new syntax directions but we were not
confident to release them yet. In the next release we'll see a removal of
features deprecated in this release and we'll continue to push ahead for
the 0.80.

(pin)