Since 2.34 you can use SSH keys to do commit signing, but my Debian 11 only comes with 2.30.

This little script is tested on Debian 11, modify as needed:

  #!/usr/bin/env bash

  which autoconf || sudo apt install -y autoconf
  which make || sudo apt install -y build-essential
  sudo apt install -y libcurl4-openssl-dev libz-dev libssl-dev libexpat-dev gettext asciidoc
  TMPD1=$(mktemp -d)
  cd $TMPD1
  wget -O git.tar.gz https://github.com/git/git/archive/refs/tags/v2.41.0.tar.gz
  gunzip git.tar.gz
  tar -xf git.tar
  rm git.tar
  cd git*
  pwd
  echo $TMPD1
  make configure
  ./configure --prefix=/usr
  make all doc
  sudo make install install-doc
  cd $HOME
  rm -rf $TMPD1
  echo Git 2.41.0 installed!
  git --version