v2.13.0

What's Changed

• Feature/corr matrix and inverse cov matrix as input in least squares function for correlated fits by @PiaLJP in #223
• fix: corrected bug that prevented combined fits with multiple x-obs in some cases by @s-kuberski in #241
• [ci] Add python 3.13 to pytest workflow. by @fjosw in #242
• [Build] Release workflow added. by @fjosw in #244

Full Changelog: v2.12.0...v2.13.0