Use golangci-lint fmt to format code (#163)

Use `golangci-lint fmt` to format code, upgrading `.golangci.yml` to v2 and mirroring the linter configuration used by https://github.com/go-gitea/gitea. `gci` now handles import ordering into standard, project-local, blank, and default groups.

Mirrors https://github.com/go-gitea/gitea/pull/37194.

Changes:
- Upgrade `.golangci.yml` to v2 format with the same linter set as gitea (minus `prealloc`, `unparam`, `testifylint`, `nilnil` which produced too many pre-existing issues)
- Add path-based exclusions (`bodyclose`, `gosec` in tests; `gosec:G115`/`G117` globally)
- Run lint via `make lint-go` in CI instead of `golangci/golangci-lint-action`, matching the pattern used by other Gitea repos
- Apply safe auto-fixes (`modernize`, `perfsprint`, `usetesting`, etc.)
- Add explanations to existing `//nolint` directives
- Remove dead code (unused `newRemoteReusableWorkflow` and `networkName`), duplicate imports, and shadowed `max` builtins
- Replace deprecated `docker/distribution/reference` with `distribution/reference`
- Fix `Deprecated:` comment casing and simplify nil/len checks

---
This PR was written with the help of Claude Opus 4.7

Reviewed-on: https://gitea.com/gitea/act/pulls/163
Reviewed-by: Lunny Xiao <xiaolunwen@gmail.com>
Co-authored-by: silverwind <me@silverwind.io>
Co-committed-by: silverwind <me@silverwind.io>

pkg/runner/job_executor_test.go

@@ -2,13 +2,16 @@ package runner
 
 import (
 	"context"
+	"errors"
 	"fmt"
 	"io"
+	"slices"
 	"testing"
 
 	"github.com/nektos/act/pkg/common"
 	"github.com/nektos/act/pkg/container"
 	"github.com/nektos/act/pkg/model"
+
 	"github.com/stretchr/testify/assert"
 	"github.com/stretchr/testify/mock"
 )
@@ -38,9 +41,9 @@ type jobInfoMock struct {
 	mock.Mock
 }
 
-func (jim *jobInfoMock) matrix() map[string]interface{} {
+func (jim *jobInfoMock) matrix() map[string]any {
 	args := jim.Called()
-	return args.Get(0).(map[string]interface{})
+	return args.Get(0).(map[string]any)
 }
 
 func (jim *jobInfoMock) steps() []*model.Step {
@@ -232,12 +235,7 @@ func TestNewJobExecutor(t *testing.T) {
 	}
 
 	contains := func(needle string, haystack []string) bool {
-		for _, item := range haystack {
-			if item == needle {
-				return true
-			}
-		}
-		return false
+		return slices.Contains(haystack, needle)
 	}
 
 	for _, tt := range table {
@@ -272,9 +270,6 @@ func TestNewJobExecutor(t *testing.T) {
 			}
 
 			for i, stepModel := range tt.steps {
-				i := i
-				stepModel := stepModel
-
 				sm := &stepMock{}
 
 				sfm.On("newStep", stepModel, rc).Return(sm, nil)
@@ -289,7 +284,7 @@ func TestNewJobExecutor(t *testing.T) {
 				sm.On("main").Return(func(ctx context.Context) error {
 					executorOrder = append(executorOrder, "step"+stepModel.ID)
 					if tt.hasError {
-						return fmt.Errorf("error")
+						return errors.New("error")
 					}
 					return nil
 				})
@@ -305,7 +300,7 @@ func TestNewJobExecutor(t *testing.T) {
 			}
 
 			if len(tt.steps) > 0 {
-				jim.On("matrix").Return(map[string]interface{}{})
+				jim.On("matrix").Return(map[string]any{})
 
 				jim.On("interpolateOutputs").Return(func(ctx context.Context) error {
 					executorOrder = append(executorOrder, "interpolateOutputs")