Resuce.hash gas usage mismatch with --network hardhat

[sveitser]

Interestingly running hardhat test --network hardhat does reproduce the original error

  1) Rescue benchmarks
       Gas spent for computing the Rescue function
         checks gas usage of TestRescue.hash:

      AssertionError: expected 91712 to equal 90363
      + expected - actual

      -91712
      +90363
      
      at Context.<anonymous> (contracts/test/benchmarks/test-rescue.js:35:34)
      at processTicksAndRejections (internal/process/task_queues.js:97:5)
      at runNextTicks (internal/process/task_queues.js:66:3)
      at listOnTimeout (internal/timers.js:523:9)
      at processTimers (internal/timers.js:497:7)

Originally posted by @NimaVaziri in #271 (comment)