apacheGH-36981: [Go] Fix ipc reader leak (apache#36982)

### Rationale for this change

Previously the ipc reader was leaking allocations.

### What changes are included in this PR?

Call `Clear()` on the memo table on final release of the ipc reader.

### Are these changes tested?

Yes

### Are there any user-facing changes?

* Closes: apache#36981

Authored-by: thorfour <me@thor-hansen.com>
Signed-off-by: Matt Topol <zotthewizard@gmail.com>

go/arrow/ipc/reader.go

@@ -159,6 +159,7 @@ func (r *Reader) Release() {
 			r.r.Release()
 			r.r = nil
 		}
+		r.memo.Clear()
 	}
 }
 

go/arrow/ipc/reader_test.go

@@ -56,3 +56,40 @@ func TestReaderCatchPanic(t *testing.T) {
 		assert.Contains(t, err.Error(), "arrow/ipc: unknown error while reading")
 	}
 }
+
+func TestReaderCheckedAllocator(t *testing.T) {
+	alloc := memory.NewCheckedAllocator(memory.NewGoAllocator())
+	defer alloc.AssertSize(t, 0)
+	schema := arrow.NewSchema([]arrow.Field{
+		{
+			Name: "s",
+			Type: &arrow.DictionaryType{
+				ValueType: arrow.BinaryTypes.String,
+				IndexType: arrow.PrimitiveTypes.Int32,
+			},
+		},
+	}, nil)
+
+	b := array.NewRecordBuilder(alloc, schema)
+	defer b.Release()
+
+	bldr := b.Field(0).(*array.BinaryDictionaryBuilder)
+	bldr.Append([]byte("foo"))
+	bldr.Append([]byte("bar"))
+	bldr.Append([]byte("baz"))
+
+	rec := b.NewRecord()
+	defer rec.Release()
+
+	buf := new(bytes.Buffer)
+	writer := NewWriter(buf, WithSchema(schema), WithAllocator(alloc))
+	defer writer.Close()
+	require.NoError(t, writer.Write(rec))
+
+	reader, err := NewReader(buf, WithAllocator(alloc))
+	require.NoError(t, err)
+	defer reader.Release()
+
+	_, err = reader.Read()
+	require.NoError(t, err)
+}