fix: Simplify create-links.bash path resolution

Replace the ~30-line get_script_dir() copy (duplicated a third time
from bashrc/bash_profile) with a one-liner. This script is always
executed directly, never sourced from another file, so BASH_SOURCE[0]
reliably points to itself — the extra logic in get_script_dir() for
the sourced-from-elsewhere case doesn't apply here.

create-links.bash

@@ -2,37 +2,7 @@
 
 # Define the path to the directory of this file if not already set
 if [ -z "${BASH_CONFIG_DIR}" ]; then
-  # Define a function to get the real path of a script
-  # (works for most cases : either sourced script or executed script, posix shells)
-  get_script_dir() {
-    local target
-    # Si appelé depuis un script (Bash), on regarde qui a appelé la fonction (${BASH_SOURCE[1]})
-    # Si la fonction est exécutée directement dans le terminal, on se rabat sur ${BASH_SOURCE[0]} ou ${0}
-    if [ -n "${BASH_SOURCE}" ]; then
-      if [ "${#BASH_SOURCE[@]}" -gt 1 ]; then
-        target="${BASH_SOURCE[1]}"
-      else
-        target="${BASH_SOURCE[0]}"
-      fi
-    elif [ -n "${ZSH_VERSION}" ]; then
-      target="${(%):-%x}"
-    else
-      target="${0}"
-    fi
-
-    # Résolution des liens symboliques POSIX
-    while [ -L "${target}" ]; do
-      local link
-      link=$(readlink "${target}")
-      case "${link}" in
-        /*) target="${link}" ;;
-        *)  target="$(dirname "${target}")/${link}" ;;
-      esac
-    done
-
-    (cd "$(dirname "${target}")" && pwd -P)
-  }
-  BASH_CONFIG_DIR=$(get_script_dir)
+  BASH_CONFIG_DIR="$(cd "$(dirname "${BASH_SOURCE[0]}")" && pwd -P)"
 fi
 
 cd "${HOME}" || exit 1