[Cherry-Pick][CI] Fix stable_test and add cherry-pick automation(6415)

[EmmonsCurse]

Cherry-pick of #6415 (authored by @EmmonsCurse) to release/2.4.

devPR:https://github.com/PaddlePaddle/FastDeploy/pull/6415 <!-- For pass CI -->

---

<!-- TemplateReference: https://github.com/PaddlePaddle/FastDeploy/blob/develop/.github/pull_request_template.md -->

Motivation

The --swap-space parameter in launch_model.sh is not required for the current CI execution environment and may introduce unnecessary or unstable behavior during model launch.

This change simplifies the launch configuration and aligns it with the actual runtime requirements.
Additionally, a dedicated cherry-pick workflow is introduced to standardize and automate cross-branch backports.

Modifications

• Removed the --swap-space parameter from launch_model.sh.
• Added a GitHub Actions workflow .github/workflows/cherry-pick.yml to support automated cherry-pick and backport operations.

Usage or Command

N/A

Accuracy Tests

N/A

Checklist

• Add at least a tag in the PR title.
  • Tag list: [[FDConfig],[APIServer],[Engine], [Scheduler], [PD Disaggregation], [Executor], [Graph Optimization], [Speculative Decoding], [RL], [Models], [Quantization], [Loader], [OP], [KVCache], [DataProcessor], [BugFix], [Docs], [CI], [Optimization], [Feature], [Benchmark], [Others], [XPU], [HPU], [GCU], [DCU], [Iluvatar], [Metax]]
  • You can add new tags based on the PR content, but the semantics must be clear.
• Format your code, run pre-commit before commit.
• Add unit tests. Please write the reason in this PR if no unit tests.
• Provide accuracy results.
• If the current PR is submitting to the release branch, make sure the PR has been submitted to the develop branch, then cherry-pick it to the release branch with the [Cherry-Pick] PR tag.

[paddle-bot]

Thanks for your contribution!