Use `rb_nogvl(..., RB_NOGVL_OFFLOAD_SAFE)` for compatibility with the fiber scheduler.

[ioquatix]

This adds RB_NOGVL_OFFLOAD_SAFE to the blocking operations that release the GVL, allowing them to be offloaded in the fiber scheduler, preventing blocking the event loop. More testing is required, but this won't affect non-fiber scheduler code paths so it should be safe to merge.

Specifically, I'll follow up with additional testing within the async gem, and we need to review if grpc itself has any thread-local storage shared during no-gvl operations (my guess is that it doesn't but I haven't explicitly checked yet).

[linux-foundation-easycla[bot]]

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• :white_check_mark: login: ioquatix / name: Samuel Williams (8f4893d1dc727e4fb364458fcc14b74900c5789d)

[arjun810]

It'd be helpful to use grpc with fibers. Anything I could do to help make it happen sooner?