Add shebangs to backup scripts so they run properly in zsh

templates/backup-mount.sh.j2

@@ -1,3 +1,4 @@
+#!/bin/bash
 source ./vars.sh
 
 MOUNT_PATH="/mnt/restic"

templates/backup-send.sh.j2

@@ -1,3 +1,4 @@
+#!/bin/bash
 ###### Unlock the restic database in case it's locked
 
 $RESTIC --password-file=$PWD_FILE unlock

templates/backup-vars.sh.j2

@@ -1,3 +1,4 @@
+#!/bin/bash
 export RESTIC_REPOSITORY="{{ restic_repository }}"
 export AWS_ACCESS_KEY_ID="{{ cloudflare_r2_access_key }}"
 export AWS_SECRET_ACCESS_KEY="{{ cloudflare_r2_secret_key }}"