samples: mcuboot upgrade only

[ktaborowski]

KRKNWK-18776

The configuration has been modified from SWAP_USING_MOVE to UPGRADE_ONLY.

We need to decide whether this change should be considered a workaround or a fix. Here are the key points to consider:

• Performance: The bootloader with SWAP_USING_MOVE takes significantly longer on the nRF54 compared to the nRF52.
• Security: The UPGRADE_ONLY configuration might be justified on the nRF54 as a security best practice.

Please review the change and provide your input on how we should classify this modification.

CI parameters

Github_actions:
  #(branch, hash, pull/XXX/head)
  NRF_revision: main

  # Do not change after creating PR
  Create_NRF_PR: false
Jenkins:
  test-sdk-sidewalk: master

Description

JIRA ticket:

Self review

• There is no commented code.
• There are no TODO/FIXME comments without associated issue ticket.
• Commits are properly organized.
• Change has been tested.
• Tests were updated (if applicable).

[github-actions]

Sample		diff	used	total

Memory usage did not change for any of the samples.

[RobertGalatNordic]

lgtm