Remove now obsolete shell script re. uAssets

tools/update-submodules.sh

@@ -1,17 +0,0 @@
-#!/usr/bin/env bash
-#
-# This script assumes a linux environment
-
-set -e
-
-echo "*** Update submodules"
-
-git submodule update --remote
-if [[ $(git diff ./submodules/) ]]; then
-    git add -u submodules/
-    git commit -m 'Update submodules'
-    git push origin master
-    echo "*** Submodules updated"
-else
-    echo "*** Submodules are already up to date"
-fi