migrate pallet-session-benchmarking to bench V2 syntax (#6294) #7302

Job	Run time
preflight / preflight	7s
preflight / ci-versions	1m 18s
test-frame-ui	27m 9s
cargo-check-benches	0s
test-full-crypto-feature	2m 43s
test-node-metrics	8m 53s
cargo-check-all-crate-macos	11m 0s
cargo-check-each-crate (1)	18m 52s
cargo-check-each-crate (2)	19m 28s
cargo-check-each-crate (3)	8m 37s
cargo-check-each-crate (4)	17m 31s
cargo-check-each-crate (5)	24m 48s
cargo-check-each-crate (6)	15m 9s
cargo-check-each-crate (7)	26m 1s
node-bench-regression-guard	9s
test-frame-examples-compile-to-wasm	3m 4s
test-deterministic-wasm	6m 35s
check-tracing	2m 33s
check-metadata-hash	6m 16s
All test misc tests passed	1s
	3h 20m 14s

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