RcppParallel no longer includes tbb headers as part of the RcppParallel/TBB.h
header, and instead only exposes its TBB-specific APIs for parallel work.

RcppParallel now bundles oneTBB 2022.0.0. Note that the TBB ABI has changed;
packages which depend on RcppParallel may need to be rebuilt.

On Windows, RcppParallel now uses the copy of TBB provided by Rtools.
If TBB is not available, RcppParallel will use only the fallback 'tinythread'
implementation. In practice, this implies that RcppParallel will now only
provide a TBB backend with R (>= 4.2.0).

Fixed builds under wasm/webR. (#237; @andrjohns)

Fixed compilation with clang-19 on Windows aarch64. (#235, #236; @andrjohns)

Fixed TBB library lookup on Windows, and removed the obsolete
TBB_USE_GCC_BUILTINS flag for Windows ARM64. TBB is statically linked
on Windows, so the package no longer tries to load TBB libraries there
at load time. (#241; @andrjohns)