[Go] IPC Reader leaks dictionary allocations

[thorfour]

Describe the bug, including details regarding any error messages, version, and platform.

The ipc reader may perform allocations to read dictionaries.

arrow/go/arrow/ipc/reader.go

Line 47 in 0fb744c

memo dictutils.Memo

However these dictionary allocations are never released

arrow/go/arrow/ipc/reader.go

Lines 150 to 163 in 0fb744c

	func (r *Reader) Release() {
	debug.Assert(atomic.LoadInt64(&r.refCount) > 0, "too many releases")
	if atomic.AddInt64(&r.refCount, -1) == 0 {
	if r.rec != nil {
	r.rec.Release()
	r.rec = nil
	}
	if r.r != nil {
	r.r.Release()
	r.r = nil
	}
	}
	}

Component(s)

Go