meta-cassini-tests: Jfrog-cli build no longer has network access

The yocto project have made changed the do_compile stage to not have network access to ensure builds are reproducible. The jfrog-cli recipe had re-enabled this access so it could use the go tools to download dependencies. This change removes that access and adds the fetching of all dependencies to the do_fetch stage.

Signed-off-by: Drew Reed Drew.Reed@arm.com