Add continuous benchmarking

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Bencher Report

Branch	1119/merge
Testbed	ubuntu-latest

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• Latency

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Benchmark	Latency	nanoseconds (ns)
tests/nest_continuous_benchmarking/test_nest_continuous_benchmarking.py::TestNESTContinuousBenchmarking::test_stdp_nn_synapse	📈 view plot ⚠️ NO THRESHOLD	4,122,786,669.60

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