prevent unecesary pre_deploy script executions

.dotter/pre_deploy.sh

@@ -2,6 +2,15 @@
 # shellcheck disable=all
 # This is a handlerbars template, so ignore issues
 
+
+checksum_file=".dotter/cache/pre_deploy.checksum"
+
+if [[ -e "$checksum_file" ]] && sha256sum --check "$checksum_file" >/dev/null 2>&1; then
+    echo "Pre deploy script has not changed, skiping script execution"
+    echo "To override this, remove the checksum file: $checksum_file"
+    exit 0
+fi
+
 {{!~ Detect the distribution ~}}
 {{~ assign "distro" (trim (command_output "awk -F= '/^ID=/ {print $2}' /etc/os-release | tr -d '\"'")) ~}}