manifest: update Sidewalk revision

[ktaborowski]

• remove child image folders
• add sidewalk file transfer dfu KRKNWK-18523 (experimental)

[NordicBuilder]

The following west manifest projects have been modified in this Pull Request:

Name	Old Revision	New Revision	Diff
sidewalk	nrfconnect/sdk-sidewalk@19c3519	nrfconnect/sdk-sidewalk#565	nrfconnect/sdk-sidewalk#565/files

Note: This message is automatically posted and updated by the Manifest GitHub Action.

[NordicBuilder]

Test specification

CI/Jenkins/NRF

• Integration Platforms

CI/Jenkins/integration

Test Module	File based changes	Manually selected	West overwrite
test-sdk-sidewalk	X

test-sdk-sidewalk: added because there was no .github/test-spec.yml in 'sidewalk'

Detailed information of selected test modules

Note: This message is automatically posted and updated by the CI

[NordicBuilder]

You can find the documentation preview for this PR at this link. It will be updated about 10 minutes after the documentation build succeeds.

Note: This comment is automatically posted by the Documentation Publishing GitHub Action.