Use crypto/sha256 (#29386)

Go 1.21 improved the performance of `crypto/sha256`. It's now similar to
`minio/sha256-simd`, so we should just use the standard libs.

https://go.dev/doc/go1.21#crypto/sha256
https://go-review.googlesource.com/c/go/+/408795
https://github.com/multiformats/go-multihash/pull/173

services/lfs/server.go

@@ -5,6 +5,7 @@ package lfs
 
 import (
 	stdCtx "context"
+	"crypto/sha256"
 	"encoding/base64"
 	"encoding/hex"
 	"errors"
@@ -33,7 +34,6 @@ import (
 	"code.gitea.io/gitea/modules/storage"
 
 	"github.com/golang-jwt/jwt/v5"
-	"github.com/minio/sha256-simd"
 )
 
 // requestContext contain variables from the HTTP request.