Improve FVP-based test runs by enabling parallel execution

FVP is useful for exercising CPU features when dedicated hardware is unavailable, but it is slow and can significantly increase CI wall-clock time. To mitigate this, run FVP-backed tests in parallel and add support tooling:

parallelize test execution and shard workloads in .gitlab-ci.yml add parallel.py to orchestrate test sharding and round-robin/bin/time-balanced strategies fetch and reuse previous artifacts to avoid re-running already-completed work reduce long job timeouts and enable job-level parallelism where appropriate This reduces overall CI latency while preserving deterministic coverage of SME/SVE/other feature paths.

Signed-off-by: Anton Bondarenko anton.bondarenko@arm.com