fix: clean up snpashot tool on download fail

[KristianDD]

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What is the current behavior?

When the download of the snapshot tools fails, the corrupted executables are not cleared and any consecutive build will fail instead of trying to download the again.

What is the new behavior?

If the download fails we remove the corrupted/partial files and the next build will try to download the again.

Fixes/Implements/Closes #591