Replace deprecated pkg/errors with Go standard library errors

Remove usage of github.com/pkg/errors and replace with
standard library errors and fmt.Errorf wrapping.

Changes:
- common/finalizer/finalizer.go
- service/worker/migration/activities.go
- remove pkg/errors direct dependency via go mod tidy

Addresses part of #9244

Made-with: Cursor

common/finalizer/finalizer.go

@@ -5,7 +5,7 @@ import (
 	"sync"
 	"time"
 
-	"github.com/pkg/errors"
+	"errors"
 	cclock "go.temporal.io/server/common/clock"
 	"go.temporal.io/server/common/goro"
 	"go.temporal.io/server/common/log"

go.mod

@@ -36,7 +36,6 @@ require (
 	github.com/nexus-rpc/sdk-go v0.5.2-0.20260211051645-26b0b4c584e5
 	github.com/olekukonko/tablewriter v0.0.5
 	github.com/olivere/elastic/v7 v7.0.32
-	github.com/pkg/errors v0.9.1
 	github.com/prometheus/client_golang v1.21.0
 	github.com/prometheus/client_model v0.6.1
 	github.com/prometheus/common v0.62.0
@@ -79,7 +78,10 @@ require (
 	modernc.org/sqlite v1.44.3
 )
 
-require github.com/grpc-ecosystem/go-grpc-middleware/v2 v2.3.2 // indirect
+require (
+	github.com/grpc-ecosystem/go-grpc-middleware/v2 v2.3.2 // indirect
+	github.com/pkg/errors v0.9.1 // indirect
+)
 
 require (
 	cel.dev/expr v0.23.1 // indirect

service/worker/migration/activities.go

@@ -7,7 +7,6 @@ import (
 	"sort"
 	"time"
 
-	"github.com/pkg/errors"
 	commonpb "go.temporal.io/api/common/v1"
 	replicationpb "go.temporal.io/api/replication/v1"
 	"go.temporal.io/api/serviceerror"
@@ -810,7 +809,7 @@ func (a *activities) verifySingleReplicationTask(
 
 		return verifyResult{
 			status: notVerified,
-		}, errors.WithMessage(err, "failed to describe workflow from the remote cluster")
+		}, fmt.Errorf("failed to describe workflow from the remote cluster: %w", err)
 	}
 }