refactor: using slices.Contains (ethereum-optimism#11521)

packages/contracts-bedrock/scripts/autogen/generate-invariant-docs/main.go

@@ -5,6 +5,7 @@ import (
 	"fmt"
 	"os"
 	"path/filepath"
+	"slices"
 	"strings"
 )
 
@@ -154,7 +155,7 @@ func docGen(invariantsDir, docsDir string) error {
 
 	for _, contract := range docs {
 		filePath := filepath.Join(docsDir, contract.Name+".md")
-		alreadyWritten := contains(writtenFiles, filePath)
+		alreadyWritten := slices.Contains(writtenFiles, filePath)
 
 		// If the file has already been written, append the extra docs to the end.
 		// Otherwise, write the file from scratch.
@@ -253,12 +254,3 @@ func renderContractDoc(contract Contract, header bool) string {
 
 	return sb.String()
 }
-
-func contains(slice []string, item string) bool {
-	for _, v := range slice {
-		if v == item {
-			return true
-		}
-	}
-	return false
-}