README: update nightly workflow badge

New workflow needs update in badge.

Signed-off-by: Giacomo Dematteis <[email protected]>

README.md

@@ -2,11 +2,11 @@
 
 #### Oncommit:
 [![Build](https://github.com/hello-nrfcloud/firmware/actions/workflows/build.yml/badge.svg)](https://github.com/hello-nrfcloud/firmware/actions/workflows/build.yml)
-[![Target tests](https://github.com/hello-nrfcloud/firmware/actions/workflows/on_target.yml/badge.svg)](https://github.com/hello-nrfcloud/firmware/actions/workflows/on_target.yml)
+[![Target tests](https://github.com/hello-nrfcloud/firmware/actions/workflows/test.yml/badge.svg)](https://github.com/hello-nrfcloud/firmware/actions/workflows/test.yml)
 [![Quality Gate Status](https://sonarcloud.io/api/project_badges/measure?project=hello-nrfcloud_firmware&metric=alert_status)](https://sonarcloud.io/summary/new_code?id=hello-nrfcloud_firmware)
 
 #### Nightly:
-[![Target_tests](https://github.com/hello-nrfcloud/firmware/actions/workflows/on_target.yml/badge.svg?event=schedule)](https://github.com/hello-nrfcloud/firmware/actions/workflows/on_target.yml?query=branch%3Amain+event%3Aschedule)
+[![Target_tests](https://github.com/hello-nrfcloud/firmware/actions/workflows/test.yml/badge.svg?event=schedule)](https://github.com/hello-nrfcloud/firmware/actions/workflows/test.yml?query=branch%3Amain+event%3Aschedule)
 
 This project is based on the
 [NCS Example Application](https://github.com/nrfconnect/ncs-example-application).