Fix linter errors

This commit and others in this branch fix
the lint errors popping up in
#1400
to unblock this PR, to allow rebase other branches
to master without getting stuck on linter errors.

Changes
* Remove io.util usage from contentcache

internal/contentcache/contentcache.go

@@ -21,7 +21,6 @@ import (
 	"fmt"
 	"io"
 	"io/fs"
-	"io/ioutil"
 	"os"
 	"path"
 	"regexp"
@@ -83,7 +82,7 @@ func (c *ContentCache) WriteMetadataCheckpointFile(cacheFileName string, cacheFi
 		return
 	}
 	metadataFileName = fmt.Sprintf("%s.json", cacheFileName)
-	err = ioutil.WriteFile(metadataFileName, file, 0644)
+	err = os.WriteFile(metadataFileName, file, 0644)
 	if err != nil {
 		err = fmt.Errorf("WriteFile for JSON metadata: %w", err)
 		return
@@ -111,7 +110,7 @@ func (c *ContentCache) recoverFileFromCache(metadataFile fs.FileInfo) {
 	}
 	var metadata CacheFileObjectMetadata
 	metadataAbsolutePath := path.Join(c.tempDir, metadataFile.Name())
-	contents, err := ioutil.ReadFile(metadataAbsolutePath)
+	contents, err := os.ReadFile(metadataAbsolutePath)
 	if err != nil {
 		logger.Errorf("content cache: Skip metadata file %v due to read error: %s", metadataFile.Name(), err)
 		return
@@ -152,11 +151,19 @@ func (c *ContentCache) RecoverCache() error {
 		c.tempDir = "/tmp"
 	}
 	logger.Infof("Recovering cache:\n")
-	files, err := ioutil.ReadDir(c.tempDir)
+	dirEntries, err := os.ReadDir(c.tempDir)
 	if err != nil {
 		// if we fail to read the specified directory, log and return error
 		return fmt.Errorf("recover cache: %w", err)
 	}
+	files := make([]os.FileInfo, len(dirEntries))
+	for i, dirEntry := range dirEntries {
+		files[i], err = dirEntry.Info()
+		if err != nil {
+			// if we fail to read the specified directory, log and return error
+			return fmt.Errorf("recover cache: %w", err)
+		}
+	}
 	for _, metadataFile := range files {
 		c.recoverFileFromCache(metadataFile)
 	}
@@ -196,7 +203,7 @@ func (c *ContentCache) AddOrReplace(cacheObjectKey *CacheObjectKey, generation i
 		cacheObject.Destroy()
 	}
 	// Create a temporary cache file on disk
-	f, err := ioutil.TempFile(c.tempDir, CacheFilePrefix)
+	f, err := os.CreateTemp(c.tempDir, CacheFilePrefix)
 	if err != nil {
 		return nil, fmt.Errorf("TempFile: %w", err)
 	}