3.07.10 please fix hints

After installation via GetIt on Delphi 12 version 3.07.10, we get the following messages when building the project:
```
[dcc32 Hint] GpLists.pas(4534): H2164 Variable 'element' is declared but never used in 'THeap.Heapify'
[dcc32 Hint] GpLists.pas(7789): H2164 Variable 'iPtr' is declared but never used in 'TGpSkipList.Create'
[dcc32 Hint] OtlParallel.pas(4486): H2077 Value assigned to 'TOmniCompute.TryValue' never used
[dcc32 Hint] OtlParallel.pas(4538): H2164 Variable 'intf' is declared but never used in 'TOmniForkJoin.Compute'
[dcc32 Hint] OtlParallel.pas(5390): H2164 Variable 'dest' is declared but never used in 'TOmniParallelMapper.Execute'
[dcc32 Hint] OtlParallel.pas(5391): H2164 Variable 'el' is declared but never used in 'TOmniParallelMapper.Execute'
```