[SL-ONLY] Optimize build behavior for the sample apps builder

[mkardous-silabs]

Description

PR optimizes the CI behavior when building the sample apps. In changes two behavior in relation to concurrency and the matrix strategies

• We prevent concurrent builds for a same reference. In other words, we cancel on-going build steps if a new build is started.
• If one of the runs in the matrix fails, it will not stop the other strategies. This will allow us to leverage the CI to determine if there a multiple failures for a change without needing to re-run the CI
• Add workflow dispatch to be able to trigger the workflow manually

manual tests to validate the scenarios