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/webhook/deliver.go

@@ -7,6 +7,7 @@ import (
 	"context"
 	"crypto/hmac"
 	"crypto/sha1"
+	"crypto/sha256"
 	"crypto/tls"
 	"encoding/hex"
 	"fmt"
@@ -29,7 +30,6 @@ import (
 	webhook_module "code.gitea.io/gitea/modules/webhook"
 
 	"github.com/gobwas/glob"
-	"github.com/minio/sha256-simd"
 )
 
 // Deliver deliver hook task