【Projects/web_api】GitHub Workflow Docker镜像打包与上传 & 优化Dockerfile占用空间

[BetterAndBetterII]

增加Github Docker 镜像打包工作流

Motivation

优化项目实际部署的体验，#1693

Modification

修改了projects/web_api/Dockerfile

不改变打包逻辑，但清除了缓存（优化Docker镜像大小，避免GitHub workflow因空间不足而报错）

需要配置阿里云的免费镜像仓库

Checklist

Before PR:

• Pre-commit or other linting tools are used to fix the potential lint issues.
• Bug fixes are fully covered by unit tests, the case that causes the bug should be added in the unit tests.
• The modification is covered by complete unit tests. If not, please add more unit test to ensure the correctness.
• The documentation has been modified accordingly, like docstring or example tutorials.

After PR:

• If the modification has potential influence on downstream or other related projects, this PR should be tested with those projects.
• CLA has been signed and all committers have signed the CLA in this PR.

[github-actions]

All contributors have signed the CLA ✍️ ✅
_{Posted by the CLA Assistant Lite bot.}

[BetterAndBetterII]

I have read the CLA Document and I hereby sign the CLA

[chupalopez]

great work