Update tipb and kvproto to use unified protobuf code

[overvenus]

Enhancement

Recently, tipb and kvproto have unified their protobuf generation options, and reduced bloated code by removing unused fields.

To update them, TiDB need to clean these paddings ¹

tidb/pkg/kv/key.go

Lines 102 to 104 in 5129bb3

	XXXNoUnkeyedLiteral struct{}
	XXXunrecognized []byte
	XXXsizecache int32

CC pingcap/kvproto#1278
CC pingcap/tipb#347

Footnotes

1. https://github.com/pingcap/kvproto/pull/1275#pullrequestreview-2431765868 ↩