Update latex template after update of pandoc in Debian Trixie

Our docker file is based on Debian Trixie.
It seems that the pandoc version in debian trixie got updated, resulting
in breaking out pdf/latex build, because pandoc creates different latex
code for citations now.

Fixing that in this buid by updating our custom latex template to what
the pandoc default latex template uses for citeproc.

theme/tex/pandoc_template.tex

@@ -338,28 +338,38 @@
 \pagestyle{$pagestyle$}
 $endif$
 $if(csl-refs)$
+% definitions for citeproc citations
+\NewDocumentCommand\citeproctext{}{}
+\NewDocumentCommand\citeproc{mm}{%
+\begingroup\def\citeproctext{#2}\cite{#1}\endgroup}
+\makeatletter
+% allow citations to break across lines
+\let\@cite@ofmt\@firstofone
+% avoid brackets around text for \cite:
+\def\@biblabel#1{}
+\def\@cite#1#2{{#1\if@tempswa , #2\fi}}
+\makeatother
 \newlength{\cslhangindent}
 \setlength{\cslhangindent}{1.5em}
 \newlength{\csllabelwidth}
 \setlength{\csllabelwidth}{3em}
-\newlength{\cslentryspacingunit} % times entry-spacing
-\setlength{\cslentryspacingunit}{\parskip}
-\newenvironment{CSLReferences}[2] % #1 hanging-ident, #2 entry spacing
- {% don't indent paragraphs
-  \setlength{\parindent}{0pt}
-  % turn on hanging indent if param 1 is 1
-  \ifodd #1
-  \let\oldpar\par
-  \def\par{\hangindent=\cslhangindent\oldpar}
-  \fi
-  % set entry spacing
-  \setlength{\parskip}{#2\cslentryspacingunit}
- }%
- {}
+\newenvironment{CSLReferences}[2] % #1 hanging-indent, #2 entry-spacing
+{\begin{list}{}{%
+	\setlength{\itemindent}{0pt}
+	\setlength{\leftmargin}{0pt}
+	\setlength{\parsep}{0pt}
+	% turn on hanging indent if param 1 is 1
+	\ifodd #1
+	\setlength{\leftmargin}{\cslhangindent}
+	\setlength{\itemindent}{-1\cslhangindent}
+	\fi
+	% set entry spacing
+	\setlength{\itemsep}{#2\baselineskip}}}
+{\end{list}}
 \usepackage{calc}
-\newcommand{\CSLBlock}[1]{#1\hfill\break}
-\newcommand{\CSLLeftMargin}[1]{\parbox[t]{\csllabelwidth}{#1}}
-\newcommand{\CSLRightInline}[1]{\parbox[t]{\linewidth - \csllabelwidth}{#1}\break}
+\newcommand{\CSLBlock}[1]{\hfill\break\parbox[t]{\linewidth}{\strut\ignorespaces#1\strut}}
+\newcommand{\CSLLeftMargin}[1]{\parbox[t]{\csllabelwidth}{\strut#1\strut}}
+\newcommand{\CSLRightInline}[1]{\parbox[t]{\linewidth - \csllabelwidth}{\strut#1\strut}}
 \newcommand{\CSLIndent}[1]{\hspace{\cslhangindent}#1}
 $endif$
 $if(lang)$