Fix tile size for matmuls with 8-bit operands in autotuner
Fix tile size for matmuls with 8-bit operands in autotuner

The result of `GetExhaustiveTritonConfigs` is cached in the autotuner class instance, so should not depend on the input dot instruction. Therefore, removing the `has_8_bit_operand` parameter from the method signature.
Instead, adjust the `block_k` attribute in the config normalization phase.

Additionally, treat 8-bit floating point types in the same manner as integer types.
