alloc profiler: adjust warnings in docs; remove logged warning from implementation

[vilterp]

Since we think we're now getting all the allocs:

• Adjust warnings in docs to just say that we're missing types for some of them (allocs profiler: extend to record Types for all allocations - (fix UnknownType in allocations results) #43688 has been updated accordingly)
• Don't log a warning anymore, and remove associated counting logic

Maybe we should still log a warning about missing types?

cc @NHDaly

[NHDaly]

Rad. Thanks Pete. I'll wait for green CI then merge!

[vilterp]

error:

Error in testset Test:
Test Failed at C:\buildbot\worker-tabularasa\tester_win64\build\share\julia\stdlib\v1.8\Test\test\runtests.jl:795
  Expression: orig == Random.default_rng()
   Evaluated: Xoshiro(0x9323c7422b2ab408, 0x571e9459461288f3, 0xfdbbd5235ca4df18, 0xbfccf06b9ac9bc6b) == TaskLocalRNG()
Error in testset Test:
Test Failed at C:\buildbot\worker-tabularasa\tester_win64\build\share\julia\stdlib\v1.8\Test\test\runtests.jl:796
  Expression: rand(orig) == rand()
   Evaluated: 0.4141655849278584 == 0.4104343156769663

Not sure what this has to do with us 🤔

[NHDaly]

Yes agreed, this one seems unrelated (maybe flaky?).
If everything is green, this should be ready to merge. (waiting on freebsd64)

[NHDaly]

(Freebsd tests never ran; there must be something wrong with the bulid bot. Going to merge now; this is mostly a docs cleanup.)