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/Metadata.py b/ethosu/vela/tflite/Metadata.py
index c0a8391..273e51e 100644
--- a/ethosu/vela/tflite/Metadata.py
+++ b/ethosu/vela/tflite/Metadata.py
@@ -3,27 +3,17 @@
 # namespace: tflite
 
 import flatbuffers
-from flatbuffers.compat import import_numpy
-np = import_numpy()
 
 class Metadata(object):
     __slots__ = ['_tab']
 
     @classmethod
-    def GetRootAs(cls, buf, offset=0):
+    def GetRootAsMetadata(cls, buf, offset):
         n = flatbuffers.encode.Get(flatbuffers.packer.uoffset, buf, offset)
         x = Metadata()
         x.Init(buf, n + offset)
         return x
 
-    @classmethod
-    def GetRootAsMetadata(cls, buf, offset=0):
-        """This method is deprecated. Please switch to GetRootAs."""
-        return cls.GetRootAs(buf, offset)
-    @classmethod
-    def MetadataBufferHasIdentifier(cls, buf, offset, size_prefixed=False):
-        return flatbuffers.util.BufferHasIdentifier(buf, offset, b"\x54\x46\x4C\x33", size_prefixed=size_prefixed)
-
     # Metadata
     def Init(self, buf, pos):
         self._tab = flatbuffers.table.Table(buf, pos)
@@ -42,19 +32,7 @@
             return self._tab.Get(flatbuffers.number_types.Uint32Flags, o + self._tab.Pos)
         return 0
 
-def Start(builder): builder.StartObject(2)
-def MetadataStart(builder):
-    """This method is deprecated. Please switch to Start."""
-    return Start(builder)
-def AddName(builder, name): builder.PrependUOffsetTRelativeSlot(0, flatbuffers.number_types.UOffsetTFlags.py_type(name), 0)
-def MetadataAddName(builder, name):
-    """This method is deprecated. Please switch to AddName."""
-    return AddName(builder, name)
-def AddBuffer(builder, buffer): builder.PrependUint32Slot(1, buffer, 0)
-def MetadataAddBuffer(builder, buffer):
-    """This method is deprecated. Please switch to AddBuffer."""
-    return AddBuffer(builder, buffer)
-def End(builder): return builder.EndObject()
-def MetadataEnd(builder):
-    """This method is deprecated. Please switch to End."""
-    return End(builder)
\ No newline at end of file
+def MetadataStart(builder): builder.StartObject(2)
+def MetadataAddName(builder, name): builder.PrependUOffsetTRelativeSlot(0, flatbuffers.number_types.UOffsetTFlags.py_type(name), 0)
+def MetadataAddBuffer(builder, buffer): builder.PrependUint32Slot(1, buffer, 0)
+def MetadataEnd(builder): return builder.EndObject()