adjust dockerfile and release build

[witchpou]

Description

add non-root user to docker file. Cleanup dockerfile and use base image

Motivation and Context

How has this been tested?

Screenshots (if appropriate):

Types of changes

• Bug fix (non-breaking change which fixes an issue)
• New feature (non-breaking change which adds functionality)
• Breaking change (fix or feature that would cause existing functionality to not work as expected)

Checklist:

• My code follows the code style of this project.
• My change requires a change to the documentation.
• I have updated the documentation accordingly.

[Copilot]

Pull Request Overview

This PR refactors the Docker build process and improves security by adding a non-root user to the Dockerfile, while also cleaning up build configurations and fixing version extraction in CI workflows.

• Replaced custom Python/Poetry installation with a base image and added non-root user for security
• Moved test target in Makefile and added actual pytest implementation
• Fixed version extraction in GitHub workflows to prevent ambiguous matches

Reviewed Changes

Copilot reviewed 5 out of 6 changed files in this pull request and generated no comments.

Show a summary per file

File	Description
Dockerfile	Replaced custom build steps with base image and added non-root user security improvements
Makefile	Reorganized test target and implemented actual pytest execution
start_make.sh	Removed entire script file
tests/test_imports.py	Added new import test for SaePositionSource
.github/workflows/create-release.yaml	Fixed version extraction to use first match only

Comments suppressed due to low confidence (2)

[flonix8]

Otherwise looks good to me.