Fdmnes updates + fully migrate struct2xas from Larch - #17

Node.js 20 actions are deprecated. The following actions are running on Node.js 20 and may not work as expected: actions/checkout@v4, conda-incubator/setup-miniconda@v2.2.0. Actions will be forced to run with Node.js 24 by default starting June 2nd, 2026. Node.js 20 will be removed from the runner on September 16th, 2026. Please check if updated versions of these actions are available that support Node.js 24. To opt into Node.js 24 now, set the FORCE_JAVASCRIPT_ACTIONS_TO_NODE24=true environment variable on the runner or in your workflow file. Once Node.js 24 becomes the default, you can temporarily opt out by setting ACTIONS_ALLOW_USE_UNSECURE_NODE_VERSION=true. For more information see: https://github.blog/changelog/2025-09-19-deprecation-of-node-20-on-github-actions-runners/

warning libmamba 'repo.anaconda.com', a commercial channel hosted by Anaconda.com, is used. warning libmamba Please make sure you understand Anaconda Terms of Services. warning libmamba See: https://legal.anaconda.com/policies/en/

WARNING conda.cli.condarc:set_key(484): Key auto_activate_base is an alias of auto_activate; setting value with latter

Mamba support is still experimental and can result in differently solved environments!