Misc ioutil deprecation adjustments

To make the tests pass.

* Replace io => os.ReadFile in magefile.go
* Adjust failing image test vs fs.DirEntry
* Adjust poller test

See #10732

magefile.go

@@ -7,7 +7,6 @@ import (
 	"bytes"
 	"errors"
 	"fmt"
-	"io"
 	"os"
 	"path"
 	"path/filepath"
@@ -298,7 +297,7 @@ func TestCoverHTML() error {
 		if err := sh.Run(goexe, "test", "-coverprofile="+cover, "-covermode=count", pkg); err != nil {
 			return err
 		}
-		b, err := io.ReadFile(cover)
+		b, err := os.ReadFile(cover)
 		if err != nil {
 			if os.IsNotExist(err) {
 				continue

resources/image_test.go

@@ -18,6 +18,7 @@ import (
 	"fmt"
 	"image"
 	"image/gif"
+	"io/fs"
 	"math/big"
 	"math/rand"
 	"os"
@@ -56,6 +57,14 @@ var eq = qt.CmpEquals(
 	cmp.Comparer(func(p1, p2 os.FileInfo) bool {
 		return p1.Name() == p2.Name() && p1.Size() == p2.Size() && p1.IsDir() == p2.IsDir()
 	}),
+	cmp.Comparer(func(d1, d2 fs.DirEntry) bool {
+		p1, err1 := d1.Info()
+		p2, err2 := d2.Info()
+		if err1 != nil || err2 != nil {
+			return false
+		}
+		return p1.Name() == p2.Name() && p1.Size() == p2.Size() && p1.IsDir() == p2.IsDir()
+	}),
 	cmp.Comparer(func(p1, p2 *genericResource) bool { return p1 == p2 }),
 	cmp.Comparer(func(m1, m2 media.Type) bool {
 		return m1.Type() == m2.Type()

watcher/filenotify/poller_test.go

@@ -34,10 +34,14 @@ func TestPollerAddRemove(t *testing.T) {
 	c.Assert(w.Add("foo"), qt.Not(qt.IsNil))
 	c.Assert(w.Remove("foo"), qt.Not(qt.IsNil))
 
-	f, err := os.CreateTemp(t.TempDir(), "asdf")
+	f, err := os.CreateTemp("", "asdf")
 	if err != nil {
 		t.Fatal(err)
 	}
+	c.Cleanup(func() {
+		c.Assert(w.Close(), qt.IsNil)
+		os.Remove(f.Name())
+	})
 	c.Assert(w.Add(f.Name()), qt.IsNil)
 	c.Assert(w.Remove(f.Name()), qt.IsNil)