Reland "[MLGO] Remove Python <3.8 from unsupported config (#106132)"

This reverts commit c3776c1.

This relands commit a959d70.

This was originally causing bot failures on Python version 3.8.
This relanding fixes that by adjusting the relevant type annotations
that are not supported in earlier versions.

Author: boomanaiden154

llvm/test/CodeGen/MLRegAlloc/Inputs/interactive_main.py

@@ -2,14 +2,15 @@
 import interactive_host
 import sys
 
+from typing import Sequence
 
 def main(args):
     # this advisor just picks the first legal register to evict, which is
     # identifiable by the "mask" feature
     class Advisor:
         to_return = False
 
-        def advice(self, tensor_values: list[log_reader.TensorValue]):
+        def advice(self, tensor_values: Sequence[log_reader.TensorValue]):
             for tv in tensor_values:
                 if tv.spec().name != "mask":
                     continue