gh-110693: Use a Larger Queue for Per-Interpreter Pending Calls (gh-118302)

gh-110693: Use a Larger Queue for Per-Interpreter Pending Calls (gh-118302)

This is an improvement over the status quo, reducing the likelihood of completely filling the pending calls queue.  However, the problem won't go away completely unless we move to an unbounded linked list or add a mechanism for waiting until the queue isn't full.