net/http/httptest: close res.Body in test

Change-Id: Ieec952ebc407ecb1aa20aa03105323505121981c
GitHub-Last-Rev: d19724c16d
GitHub-Pull-Request: golang/go#66263
Reviewed-on: https://go-review.googlesource.com/c/go/+/570915
Auto-Submit: Damien Neil <dneil@google.com>
LUCI-TryBot-Result: Go LUCI <golang-scoped@luci-project-accounts.iam.gserviceaccount.com>
Run-TryBot: Emmanuel Odeke <emmanuel@orijtech.com>
TryBot-Result: Gopher Robot <gobot@golang.org>
Reviewed-by: David Chase <drchase@google.com>
Reviewed-by: Emmanuel Odeke <emmanuel@orijtech.com>
Reviewed-by: Damien Neil <dneil@google.com>

src/net/http/httptest/server_test.go

@@ -83,6 +83,7 @@ func testGetAfterClose(t *testing.T, newServer newServerFunc) {
 		t.Fatal(err)
 	}
 	got, err := io.ReadAll(res.Body)
+	res.Body.Close()
 	if err != nil {
 		t.Fatal(err)
 	}