Report firtool version when firtool invocation errors (backport #3174) (#3175)

* Report firtool version when firtool invocation errors (#3174)

* the firtool version is now included in the BuildInfo
* firtool now must be on the path when publishing, but is not required
  for building or testing
* FirtoolNonZeroExitCode now no longer includes a stack trace

(cherry picked from commit 06b569da

)

# Conflicts:
#	build.sbt

* Resolve backport conflicts

* [CI] Install firtool in the publish step (#3176)

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Co-authored-by: Jack Koenig <koenig@sifive.com>