Revert "[mlir][mesh] adding shard-size control (#98145)"
This reverts commit fca69838caf19854769ada21a71da91fcfcbde73.
Also reverts the fixup: "[mlir] Fix -Wunused-variable in MeshOps.cpp (NFC)"
This reverts commit fc737368fe6e27d6ecf76e522cb43a32aaca992a.
