Align step failure log output with GitHub Actions (#927)

Fixes #926.

Before:

<img src="/attachments/a5ae9221-eee2-410a-964e-6103ce126df4" alt="image.png" width="400">

After:

<img width="400" alt="image.png" src="attachments/2f2d67c4-6080-4ec3-9ae5-df33e6479920">

Also gets rid of a bunch of emojis in the logging and the obsolete link to `nektos/act` and align some other error messages.

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

---------

Co-authored-by: Nicolas <bircni@icloud.com>
Reviewed-on: https://gitea.com/gitea/runner/pulls/927
Reviewed-by: Nicolas <bircni@icloud.com>
Co-authored-by: silverwind <me@silverwind.io>
Co-committed-by: silverwind <me@silverwind.io>

act/container/docker_run.go

@@ -633,14 +633,10 @@ func (cr *containerReference) exec(cmd []string, env map[string]string, user, wo
 			return fmt.Errorf("failed to inspect exec: %w", err)
 		}
 
-		switch inspectResp.ExitCode {
-		case 0:
+		if inspectResp.ExitCode == 0 {
 			return nil
-		case 127:
-			return fmt.Errorf("exitcode '%d': command not found, please refer to https://github.com/nektos/act/issues/107 for more information", inspectResp.ExitCode)
-		default:
-			return fmt.Errorf("exitcode '%d': failure", inspectResp.ExitCode)
 		}
+		return ExitCodeError(inspectResp.ExitCode)
 	}
 }
 
@@ -930,7 +926,7 @@ func (cr *containerReference) wait() common.Executor {
 			return nil
 		}
 
-		return fmt.Errorf("exit with `FAILURE`: %v", statusCode)
+		return ExitCodeError(statusCode)
 	}
 }