refactor(translator, executor): remove redundant bytes.Clone calls for improved performance

- Replaced all instances of `bytes.Clone` with direct references to enhance efficiency.
- Simplified payload handling across executors and translators by eliminating unnecessary data duplication.

internal/translator/gemini/gemini/gemini_gemini_request.go

@@ -4,7 +4,6 @@
 package gemini
 
 import (
-	"bytes"
 	"fmt"
 
 	"github.com/router-for-me/CLIProxyAPI/v6/internal/translator/gemini/common"
@@ -19,7 +18,7 @@ import (
 //
 // It keeps the payload otherwise unchanged.
 func ConvertGeminiRequestToGemini(_ string, inputRawJSON []byte, _ bool) []byte {
-	rawJSON := bytes.Clone(inputRawJSON)
+	rawJSON := inputRawJSON
 	// Fast path: if no contents field, only attach safety settings
 	contents := gjson.GetBytes(rawJSON, "contents")
 	if !contents.Exists() {