Failt unit test on ARM64

[Jean-Romain]

Linux ARM64 is ok

    Running the tests in 'tests/testthat.R' failed.
    Last 13 lines of output:
      ── Failure ('test-qsm.R:48:3'): write and read preserve qsm ────────────────────
      Expected `sum(qsm1$branch_order == 3)` to equal 823L.
      Differences:
      1/1 mismatches
      [1] 783 - 823 == -40
      ── Failure ('test-qsm.R:49:3'): write and read preserve qsm ────────────────────
      Expected `sum(qsm3$branch_order == 3)` to equal 823L.
      Differences:
      1/1 mismatches
      [1] 783 - 823 == -40
      
      [ FAIL 4 | WARN 0 | SKIP 0 | PASS 113 ]