chore: update deps, adapt lint, use json v2 (#1185)

- Raised go to 1.27
- Adopted json v2
- Sync lint config from gitea
- Fixed all issues

Co-authored-by: silverwind <me@silverwind.io>
Reviewed-on: https://gitea.com/gitea/runner/pulls/1185
Reviewed-by: bircni <bircni@icloud.com>
Co-authored-by: Renovate Bot <renovate-bot@gitea.com>

internal/app/run/health_check.go

@@ -87,8 +87,7 @@ func executeHealthCheck(ctx context.Context, script string, timeout time.Duratio
 	if err == nil {
 		return nil
 	}
-	var exitErr *exec.ExitError
-	if errors.As(err, &exitErr) {
+	if exitErr, ok := errors.AsType[*exec.ExitError](err); ok {
 		return fmt.Errorf("exited with code %d", exitErr.ExitCode())
 	}
 	return err

internal/app/run/post_task_script.go

@@ -74,8 +74,7 @@ func (r *Runner) runPostTaskScript(ctx context.Context, reporter *report.Reporte
 			log.Warnf("post-task script %q for task %d: %v", script, task.Id, err)
 			return
 		}
-		var exitErr *exec.ExitError
-		if errors.As(err, &exitErr) {
+		if exitErr, ok := errors.AsType[*exec.ExitError](err); ok {
 			log.Warnf("post-task script %q for task %d exited with code %d", script, task.Id, exitErr.ExitCode())
 			return
 		}

internal/app/run/runner.go

@@ -6,7 +6,7 @@ package run
 import (
 	"bytes"
 	"context"
-	"encoding/json"
+	"encoding/json/v2"
 	"errors"
 	"fmt"
 	"maps"
@@ -676,7 +676,7 @@ func postInternalCache(url, secret string, body map[string]any) (map[string]any,
 	}
 	answer := map[string]any{}
 	// A server too old to answer with a body is not an error, it simply tells us nothing.
-	_ = json.NewDecoder(resp.Body).Decode(&answer)
+	_ = json.UnmarshalRead(resp.Body, &answer)
 	return answer, nil
 }
 

internal/app/run/runner_cache_test.go

@@ -5,7 +5,7 @@ package run
 
 import (
 	"bytes"
-	"encoding/json"
+	"encoding/json/v2"
 	"fmt"
 	"io"
 	"net/http"
@@ -152,7 +152,7 @@ func TestRunner_CacheFullFlow_MatchesToolkit(t *testing.T) {
 
 func decodeJSON(resp *http.Response, v any) error {
 	defer resp.Body.Close()
-	return json.NewDecoder(resp.Body).Decode(v)
+	return json.UnmarshalRead(resp.Body, v)
 }
 
 // End-to-end against a remote cache-server: token unknown → 401, register →