fix: replace depracted io/ioutil package with os package

pkg/modules/api/formdata.go

@@ -2,8 +2,8 @@ package api
 
 import (
 	"fmt"
-	"io/ioutil"
 	"net/http"
+	"os"
 	"path/filepath"
 	"sort"
 	"strconv"
@@ -426,7 +426,7 @@ func (form *FormData) mandatoryPath(filename string, target *string) *FormData {
 // readFile binds the content of a file to a string variable. It populates an
 // error if it fails to read the file content.
 func (form *FormData) readFile(path, filename string, target *string) *FormData {
-	b, err := ioutil.ReadFile(path)
+	b, err := os.ReadFile(path)
 	if err != nil {
 		form.append(
 			fmt.Errorf("form file '%s' is invalid (%w)", filename, err),

pkg/modules/chromium/chromium.go

@@ -4,7 +4,6 @@ import (
 	"context"
 	"errors"
 	"fmt"
-	"io/ioutil"
 	"os"
 	"regexp"
 	"strings"
@@ -808,7 +807,7 @@ func (mod Chromium) PDF(ctx context.Context, logger *zap.Logger, URL, outputPath
 		return fmt.Errorf("%v: %w", consoleExceptions, ErrConsoleExceptions)
 	}
 
-	err = ioutil.WriteFile(outputPath, buffer, 0600)
+	err = os.WriteFile(outputPath, buffer, 0600)
 	if err != nil {
 		return fmt.Errorf("write result to output path: %w", err)
 	}

pkg/modules/chromium/routes.go

@@ -6,7 +6,6 @@ import (
 	"errors"
 	"fmt"
 	"html/template"
-	"io/ioutil"
 	"net/http"
 	"os"
 	"path/filepath"
@@ -271,7 +270,7 @@ func convertMarkdownRoute(chromium API, engine gotenberg.PDFEngine) api.Route {
 							return "", nil
 						}
 
-						b, err := ioutil.ReadFile(path)
+						b, err := os.ReadFile(path)
 						if err != nil {
 							return "", fmt.Errorf("read markdown file '%s': %w", filename, err)
 						}