Enhance Docker build workflow with caching, testing, and vulnerability scanning

[coderabbitai]

As discussed in PR #58, there are suggestions to improve the Docker build workflow for the SDM Docker image.

Suggestions:

• Add build caching to speed up builds.
• Add more comprehensive testing.
• Add vulnerability scanning to enhance security.

These changes would make the workflow more efficient and secure.

Reference comment: Discussion

Requested by @aaronsteers.

[natikgadzhi]

What?