Remove preamble section for differente compilers

notebook-preamble.tex

@@ -21,19 +21,8 @@
 \usepackage{upquote} % Upright quotes for verbatim code
 \usepackage{eurosym} % defines \euro
 
-\usepackage{iftex}
-\ifPDFTeX
-    \usepackage[T1]{fontenc}
-    \IfFileExists{alphabeta.sty}{
-        \usepackage{alphabeta}
-    }{
-        \usepackage[mathletters]{ucs}
-        \usepackage[utf8x]{inputenc}
-    }
-\else
-    \usepackage{fontspec}
-    \usepackage{unicode-math}
-\fi
+\usepackage{fontspec}
+\usepackage{unicode-math}
 
 \usepackage{fancyvrb} % verbatim replacement that allows latex
 \usepackage{grffile} % extends the file name processing of package graphics
@@ -56,7 +45,7 @@
 
 \usepackage{longtable} % longtable support required by pandoc >1.10
 \usepackage{booktabs}  % table support for pandoc > 1.12.2
-\usepackage{array}     % table support for pandoc >= 2.11.3
+%\usepackage{array}     % table support for pandoc >= 2.11.3
 \usepackage{calc}      % table minipage width calculation for pandoc >= 2.11.1
 \usepackage[inline]{enumitem} % IRkernel/repr support (it uses the enumerate* environment)
 \usepackage[normalem]{ulem} % ulem is needed to support strikethroughs (\sout)