Running the fuzzer requires some hoop jumping and some problems only
show up in containers. This basically replicates the build-oss-fuzz
job from our CI so we can run in the same containers we use in CI.

Reviewed-by: Alexander Bulekov <alxndr@bu.edu>
Signed-off-by: Alex Bennée <alex.bennee@linaro.org>
Message-Id: <20230630180423.558337-10-alex.bennee@linaro.org>