internal/task: delete constant timeouts to deflake tests

The motivation is the same as described in the commit message
of https://go.dev/cl/504495.

For golang/go#64110.
Fixes golang/go#66282.

Change-Id: I21bb9b9fd5934dc4ac30da671d7c3e913824d2c6
Reviewed-on: https://go-review.googlesource.com/c/build/+/585421
Reviewed-by: Roland Shoemaker <[email protected]>
Reviewed-by: Dmitri Shuralyov <[email protected]>
Auto-Submit: Dmitri Shuralyov <[email protected]>
LUCI-TryBot-Result: Go LUCI <[email protected]>

Author: dmitshur

internal/task/privx_test.go

@@ -12,7 +12,6 @@ import (
 	"reflect"
 	"strings"
 	"testing"
-	"time"
 
 	"golang.org/x/build/gerrit"
 	"golang.org/x/build/internal/workflow"
@@ -123,9 +122,7 @@ echo`), 0777); err != nil {
 	if err != nil {
 		t.Fatal(err)
 	}
-	ctx, cancel := context.WithTimeout(context.Background(), time.Minute)
-	defer cancel()
-	_, err = w.Run(ctx, &verboseListener{t: t})
+	_, err = w.Run(context.Background(), &verboseListener{t: t})
 	if err != nil {
 		t.Fatal(err)
 	}

internal/task/sync_private_test.go

@@ -4,7 +4,6 @@ import (
 	"context"
 	"strings"
 	"testing"
-	"time"
 
 	"golang.org/x/build/internal/workflow"
 )
@@ -30,9 +29,7 @@ func TestSyncPrivate(t *testing.T) {
 	if err != nil {
 		t.Fatal(err)
 	}
-	ctx, cancel := context.WithTimeout(context.Background(), time.Minute)
-	defer cancel()
-	_, err = w.Run(ctx, &verboseListener{t: t})
+	_, err = w.Run(context.Background(), &verboseListener{t: t})
 	if err != nil {
 		t.Fatal(err)
 	}

internal/task/updateproxytestrepo_test.go

@@ -8,7 +8,6 @@ import (
 	"context"
 	"fmt"
 	"testing"
-	"time"
 
 	"golang.org/x/build/internal/workflow"
 )
@@ -44,8 +43,7 @@ func TestUpdateProxyTestRepo(t *testing.T) {
 				Branch:    "master",
 			}
 
-			ctx, cancel := context.WithTimeout(context.Background(), time.Minute)
-			defer cancel()
+			ctx := context.Background()
 			if _, err := upgradeGoVersion.UpdateProxyTestRepo(&workflow.TaskContext{Context: ctx}, Published{Version: "go" + tt.new}); err != nil {
 				t.Fatal(err)
 			}