[CODE] NNPDF/nnpdf: 4.0.8

Minor changes and bugfixing with respect to 4.0.7 in preparation for the final releases of the QED and MHOU PDFs. QED PDFs published as: "Photons in the proton: implications for the LHC" 2401.08749 MHOU PDFs published as: "Determination of the theory uncertainties from missing higher orders on NNLO parton distributions with percent accuracy" 2401.10319 This tag can be used to reproduce the PDF sets released alongside the two papers above and which can be found in the NNPDF website: MHOU QED What's Changed Theories added (799, 800, 803) [bot] Add conda environment for tag 4.0.7 by @github-actions in https://github.com/NNPDF/nnpdf/pull/1892 also upload conda package if push corresponds to a tag creation by @RoyStegeman in https://github.com/NNPDF/nnpdf/pull/1897 Fix dataset/prediction ordering problem in theory covmat creation by @RoyStegeman in https://github.com/NNPDF/nnpdf/pull/1899 add description of 4.0.7 release to docs by @RoyStegeman in https://github.com/NNPDF/nnpdf/pull/1900 Restore needed thcovmat functions by @andreab1997 in https://github.com/NNPDF/nnpdf/pull/1901 Bugfixes Fix alphaem running by @niclaurenti in https://github.com/NNPDF/nnpdf/pull/1906 make vp-nextfitruncard use Q0 instead of Qmin for iterating preprocessing by @niclaurenti in https://github.com/NNPDF/nnpdf/pull/1898 Full Changelog: https://github.com/NNPDF/nnpdf/compare/4.0.7...4.0.8

Zaharid, Juan M. Cruz-Martinez, Stefano Carrazza, Rosalyn Pearson, Cameron Voisey, wilsonmr, Andrea Barontini, Roy Stegeman, Nathan Hartland, Niccolò Laurenti, Aron Jansen, Emanuele R. Nocera, Luca Rottoli, Rabah Abdul Khalek, Emma Slade, Giacomo Magni, Mark Nestor Costantini, siranipour, Carlos Murilo Romero Rocha, … Samuele Voltan. (2024). NNPDF/nnpdf: 4.0.8 (4.0.8). Zenodo. https://doi.org/10.5281/zenodo.10550938