I need to make the following code work so that I can get a table with an automatic calculation of column separation based on the number of columns to make it fit the whole \linewidth.
\documentclass[a4paper]{article}
\usepackage{booktabs,mathtools,siunitx}
\usepackage{tabularray}
\UseTblrLibrary{booktabs,siunitx}
\sisetup{
table-format = 2.2,
round-precision = 2,
round-mode = places,
round-integer-to-decimal = true
}
\begin{document}
\begin{tblr}{
colsep = 0 mm,
colspec = {@{\extracolsep{\fill}} *{2}{>{$\relax}X<{$}} *{4}{S}},
row{1} = {font=\boldmath\bfseries},
}
\toprule
& \delta [deg] & {{{5}}} & {{{10}}} & {{{15}}} & {{{20}}} \\
\midrule
\Gamma = x^2 & \beta [deg] & 1 & 2 & 3 & 4 \\
\bottomrule
\end{tblr}
\end{document}

