docs: address issue #23891 (#23957)

## Summary
Fixed Docker Desktop Ubuntu installation commands to use `apt install`
instead of `apt-get install` for local .deb files.

## Changes
- Changed `apt-get install` to `apt install` in the Install Docker
Desktop section
- Changed `apt-get install` to `apt install` in the Upgrade Docker
Desktop section
- Kept `apt-get update` unchanged (works correctly)

Fixes #23891

---
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content/manuals/desktop/setup/install/linux/ubuntu.md

@@ -1,7 +1,9 @@
 ---
-description: Learn how to install, launch, and upgrade Docker Desktop on Ubuntu. This
+description:
+  Learn how to install, launch, and upgrade Docker Desktop on Ubuntu. This
   quick guide will cover prerequisites, installation methods, and more.
-keywords: install docker ubuntu, ubuntu install docker, install docker on ubuntu,
+keywords:
+  install docker ubuntu, ubuntu install docker, install docker on ubuntu,
   docker install ubuntu, how to install docker on ubuntu, ubuntu docker install, docker
   installation on ubuntu, docker ubuntu install, docker installing ubuntu, installing
   docker on ubuntu, docker desktop for ubuntu
@@ -10,9 +12,9 @@ linkTitle: Ubuntu
 weight: 10
 toc_max: 4
 aliases:
-- /desktop/linux/install/ubuntu/
-- /desktop/install/ubuntu/
-- /desktop/install/linux/ubuntu/
+  - /desktop/linux/install/ubuntu/
+  - /desktop/install/ubuntu/
+  - /desktop/install/linux/ubuntu/
 ---
 
 > **Docker Desktop terms**
@@ -47,7 +49,7 @@ Recommended approach to install Docker Desktop on Ubuntu:
 
    ```console
    $ sudo apt-get update
-   $ sudo apt-get install ./docker-desktop-amd64.deb
+   $ sudo apt install ./docker-desktop-amd64.deb
    ```
 
    > [!NOTE]
@@ -68,7 +70,7 @@ The post-install script:
 - Sets the capability on the Docker Desktop binary to map privileged ports and set resource limits.
 - Adds a DNS name for Kubernetes to `/etc/hosts`.
 - Creates a symlink from `/usr/local/bin/com.docker.cli` to `/usr/bin/docker`.
-  This is because the classic Docker CLI is installed at `/usr/bin/docker`. The Docker Desktop installer also installs a Docker CLI binary that includes cloud-integration capabilities and is essentially a wrapper for the Compose CLI, at `/usr/local/bin/com.docker.cli`. The symlink ensures that the wrapper can access the classic Docker CLI. 
+  This is because the classic Docker CLI is installed at `/usr/bin/docker`. The Docker Desktop installer also installs a Docker CLI binary that includes cloud-integration capabilities and is essentially a wrapper for the Compose CLI, at `/usr/local/bin/com.docker.cli`. The symlink ensures that the wrapper can access the classic Docker CLI.
 
 ## Launch Docker Desktop
 
@@ -80,7 +82,7 @@ When a new version for Docker Desktop is released, the Docker UI shows a notific
 You need to download the new package each time you want to upgrade Docker Desktop and run:
 
 ```console
-$ sudo apt-get install ./docker-desktop-amd64.deb
+$ sudo apt install ./docker-desktop-amd64.deb
 ```
 
 ## Next steps