docs: remove reference to Node.js download less common os (#8418)

## Situation

External URL:
https://docs.npmjs.com/downloading-and-installing-node-js-and-npm#less-common-operating-systems
Source URL:
https://github.com/npm/documentation/blob/main/content/getting-started/configuring-your-local-environment/downloading-and-installing-node-js-and-npm.mdx#less-common-operating-systems

- The target URL https://nodejs.org/en/download/package-manager/
redirects to https://nodejs.org/en/download
- The original content, last seen on Mar 18, 2024, viewable on
https://web.archive.org/web/20240318015303/https://nodejs.org/en/download/package-manager/
previously contained a list that included operating systems which could
be considered as "less common"

The following screenshot shows content that Node.js has already deleted:


![image](https://github.com/user-attachments/assets/68ac3505-fd51-4433-b184-e03d590d2177)

- There is no longer a section on
https://nodejs.org/en/download/package-manager/ corresponding to
"Less-common operating systems" and the redirected url
https://nodejs.org/en/download currently limits itself to:
  - Windows
  - macOS
  - Linux
  - AIX

This is a screenshot of the current contents of
https://nodejs.org/en/download:


![image](https://github.com/user-attachments/assets/e936afc3-8ab0-4c49-a02f-820de5836a70)


## Change

In
[docs/lib/content/configuring-npm/install.md](https://github.com/npm/cli/blob/latest/docs/lib/content/configuring-npm/install.md):

- remove the section "Less-common operating systems" since there is no
longer any corresponding target information available

## References

- related to npm/documentation#1459

Author: MikeMcC399

docs/lib/content/configuring-npm/install.md

@@ -69,10 +69,3 @@ installers:
 
 Or see [this page](https://nodejs.org/en/download/package-manager/) to
 install npm for Linux in the way many Linux developers prefer.
-
-#### Less-common operating systems
-
-For more information on installing Node.js on a variety of operating
-systems, see [this page][pkg-mgr].
-
-[pkg-mgr]: https://nodejs.org/en/download/package-manager/