Revert reversion of TensorFlow 2.9 update

With the errors caused by the previous TensorFlow 2.9 update
being fixed, we can proceed with the upgrade.

Signed-off-by: erik.andersson@arm.com <erik.andersson@arm.com>
Change-Id: Ie1f025e8d984efaebc68b8d051126d49bee6b2b8
diff --git a/ethosu/vela/tflite/UnpackOptions.py b/ethosu/vela/tflite/UnpackOptions.py
index b70b040..eed4019 100644
--- a/ethosu/vela/tflite/UnpackOptions.py
+++ b/ethosu/vela/tflite/UnpackOptions.py
@@ -3,27 +3,17 @@
 # namespace: tflite
 
 import flatbuffers
-from flatbuffers.compat import import_numpy
-np = import_numpy()
 
 class UnpackOptions(object):
     __slots__ = ['_tab']
 
     @classmethod
-    def GetRootAs(cls, buf, offset=0):
+    def GetRootAsUnpackOptions(cls, buf, offset):
         n = flatbuffers.encode.Get(flatbuffers.packer.uoffset, buf, offset)
         x = UnpackOptions()
         x.Init(buf, n + offset)
         return x
 
-    @classmethod
-    def GetRootAsUnpackOptions(cls, buf, offset=0):
-        """This method is deprecated. Please switch to GetRootAs."""
-        return cls.GetRootAs(buf, offset)
-    @classmethod
-    def UnpackOptionsBufferHasIdentifier(cls, buf, offset, size_prefixed=False):
-        return flatbuffers.util.BufferHasIdentifier(buf, offset, b"\x54\x46\x4C\x33", size_prefixed=size_prefixed)
-
     # UnpackOptions
     def Init(self, buf, pos):
         self._tab = flatbuffers.table.Table(buf, pos)
@@ -42,19 +32,7 @@
             return self._tab.Get(flatbuffers.number_types.Int32Flags, o + self._tab.Pos)
         return 0
 
-def Start(builder): builder.StartObject(2)
-def UnpackOptionsStart(builder):
-    """This method is deprecated. Please switch to Start."""
-    return Start(builder)
-def AddNum(builder, num): builder.PrependInt32Slot(0, num, 0)
-def UnpackOptionsAddNum(builder, num):
-    """This method is deprecated. Please switch to AddNum."""
-    return AddNum(builder, num)
-def AddAxis(builder, axis): builder.PrependInt32Slot(1, axis, 0)
-def UnpackOptionsAddAxis(builder, axis):
-    """This method is deprecated. Please switch to AddAxis."""
-    return AddAxis(builder, axis)
-def End(builder): return builder.EndObject()
-def UnpackOptionsEnd(builder):
-    """This method is deprecated. Please switch to End."""
-    return End(builder)
\ No newline at end of file
+def UnpackOptionsStart(builder): builder.StartObject(2)
+def UnpackOptionsAddNum(builder, num): builder.PrependInt32Slot(0, num, 0)
+def UnpackOptionsAddAxis(builder, axis): builder.PrependInt32Slot(1, axis, 0)
+def UnpackOptionsEnd(builder): return builder.EndObject()