perf(lib): iterate s.policy.Bots by index to drop per-call heap copy (#1639)

Signed-off-by: jvoisin <julien.voisin@dustri.org>

internal/hash.go

@@ -11,9 +11,8 @@ import (
 // SHA256sum computes a cryptographic hash. Still used for proof-of-work challenges
 // where we need the security properties of a cryptographic hash function.
 func SHA256sum(text string) string {
-	hash := sha256.New()
-	hash.Write([]byte(text))
-	return hex.EncodeToString(hash.Sum(nil))
+	sum := sha256.Sum256([]byte(text))
+	return hex.EncodeToString(sum[:])
 }
 
 // FastHash is a high-performance non-cryptographic hash function suitable for