fix: handle GPG key for Docker repo

[cnvergence]

What this PR does / why we need it:
Coming from the customer issue, PR will fix the deprecated warning

W: https://download.docker.com/linux/ubuntu/dists/jammy/InRelease: Key is stored in legacy trusted.gpg keyring (/etc/apt/trusted.gpg), see the DEPRECATION section in apt-key(8) for details.
curl -fsSL https://download.docker.com/linux/ubuntu/gpg | apt-key add -
Warning: apt-key is deprecated. Manage keyring files in trusted.gpg.d instead (see apt-key(8)).
OK

Which issue(s) this PR fixes:

Fixes #387

What type of PR is this?

Special notes for your reviewer:

Does this PR introduce a user-facing change? Then add your Release Note here:

Handle GPG key for Docker repo

Documentation:

NONE

[ahmedwaleedmalik]

/approve

Thanks for taking care of this 👍

[kubermatic-bot]

LGTM label has been added.

Git tree hash: 5ecdfe4932f3cb79525d1c30cb824ef4ba5222a9

[kubermatic-bot]

[APPROVALNOTIFIER] This PR is APPROVED

This pull-request has been approved by: ahmedwaleedmalik

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