Migrate to ccpbiosim Organisaion

[harryswift01]

Summary

This PR updates the mdprep GitHub Actions workflow to fix test execution issues and align the repository with the CCPBioSim organisation. The workflow was previously hanging during the testing stage, and several configuration updates were required to ensure smooth CI runs and correct organisational references.

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Changes

Change 1: Fix and modernise CI workflow

• Updated .github/workflows/python-app.yml to resolve hanging tests.
• Ensured Conda environment creation and activation work correctly across all OS platforms (Ubuntu, macOS, Windows).
• Added diagnostic steps (conda info, conda list) for debugging during CI runs.
• Confirmed pytest runs successfully with coverage reporting enabled.

Change 2: Update organisation references

• Updated all repository and configuration references from hecbiosim → CCPBioSim.

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Impact

• CI workflow for mdprep now runs successfully and consistently across all supported platforms.
• Streamlines automated testing and improves maintainability.
• Aligns repository and workflows under the CCPBioSim organisation for better integration and visibility.

[Rob-Welch]

Thanks Harry!