[DOCS] Use gpg instead of apt-key add to add the GPG key to APT keyrings directory (openvinotoolkit#26922)

### Details:

Since `apt-key add` is deprecated, I tried by myself to instead use the
`gpg` command to add the GPG key to APT keyrings directory.

This is what I tried on my own:
<https://gist.github.com/ytxmobile98/b198a8ef4d2affd713780b16159a6618#file-install-md>

### Tickets:
 - *ticket-id*

Co-authored-by: Ilya Lavrenov <ilya.lavrenov@intel.com>

Author: ytxmobile98

.github/workflows/job_debian_packages.yml

@@ -50,14 +50,14 @@ jobs:
             # Install debian packages from previous release
             apt-get install --no-install-recommends -y gnupg wget ca-certificates lsb-release
             wget https://apt.repos.intel.com/intel-gpg-keys/GPG-PUB-KEY-INTEL-SW-PRODUCTS.PUB
-            apt-key add GPG-PUB-KEY-INTEL-SW-PRODUCTS.PUB
-            
+            gpg --output /etc/apt/trusted.gpg.d/intel.gpg --dearmor GPG-PUB-KEY-INTEL-SW-PRODUCTS.PUB
+
             # Yields only the number, e.g., "20"
             ubuntu_version=$(lsb_release -r -s)
             ubuntu_version=${ubuntu_version%.*}
-            
+
             echo "deb https://apt.repos.intel.com/openvino/2024 ubuntu$ubuntu_version main" | tee /etc/apt/sources.list.d/intel-openvino-2024.list
-            
+
             apt-get update -y
             apt-get install -y openvino
           fi

docs/articles_en/get-started/install-openvino/install-openvino-apt.rst

@@ -37,7 +37,7 @@ Step 1: Set Up the OpenVINO Toolkit APT Repository
 
       .. code-block:: sh
 
-         sudo apt-key add GPG-PUB-KEY-INTEL-SW-PRODUCTS.PUB
+         sudo gpg --output /etc/apt/trusted.gpg.d/intel.gpg --dearmor GPG-PUB-KEY-INTEL-SW-PRODUCTS.PUB
 
       .. note::