fix: typo in substrait

[waynexia]

Which issue does this PR close?

Closes #.

Rationale for this change

Try to encode - in substrait will report an error that "substract" is not supported

 170   │ 2023-08-08T03:52:46.109050Z  WARN servers::mysql::server: Internal error occurred during query exec, server actively close the channel to let client try next time: Failed to collect recordbatch, source: Failed to poll stream, source: External error: External er
       │ ror, source: Failed to request remote peer, source: Failed to do Flight get, code: Internal error, source: This feature is not implemented: Unsupported function name: "substract".

What changes are included in this PR?

Correct typo "substract" to "subtract"

Are these changes tested?

Yes

Are there any user-facing changes?

No