autopkgtest fails on armhf (almost all the time)

[Balint Reczey]

https://autopkgtest.ubuntu.com/packages/r/ruby-stackprof/groovy/arm64

https://objectstorage.prodstack4-5.canonical.com/v1/AUTH_77e2ada1e7a84929a74ba3b87153c0ac/autopkgtest-groovy/groovy/arm64/r/ruby-stackprof/20210106_142905_30170@/log.gz
...
  1) Failure:
StackProfTest#test_gc [/tmp/autopkgtest.L8qJvd/build.VwF/src/test/test_stackprof.rb:194]:
Expected 34 to be <= 25.

28 runs, 83 assertions, 1 failures, 0 errors, 0 skips
...