Revert "tests: Add context cancelation (#15374)"

This reverts commit 1e332f0eb1.

Reverting this as tests are failing randomly.

cmd/signature-v4_test.go

@@ -18,7 +18,6 @@
 package cmd
 
 import (
-	"context"
 	"fmt"
 	"net/http"
 	"net/url"
@@ -94,10 +93,7 @@ func TestDoesPolicySignatureMatch(t *testing.T) {
 }
 
 func TestDoesPresignedSignatureMatch(t *testing.T) {
-	ctx, cancel := context.WithCancel(context.Background())
-	defer cancel()
-
-	obj, fsDir, err := prepareFS(ctx)
+	obj, fsDir, err := prepareFS()
 	if err != nil {
 		t.Fatal(err)
 	}