marginaleffects: Do not use attributes like posterior_draws

[strengejacke]

Fixes #556

Fixed packages:

• insight
• bayestestR
• parameters
• modelbased

Waiting for vincentarelbundock/marginaleffects#1570

[gemini-code-assist]

Code Review

This pull request updates the package version and adds marginaleffects to the Remotes in the DESCRIPTION file. While the changes are functional, I have provided two suggestions to improve maintainability and reproducibility. The first recommends a minor version bump to align with semantic versioning, given the new features introduced. The second suggests pinning the remote dependency to a specific reference to ensure consistent builds.

[strengejacke]

@gemini-code-assist review