feat: remove the broken Zooming Image Tool

The Zooming Image Tool does not load properly, currently, and even if it
did, relying on an external Javascript to function across releases is
not something we can support.  Thus, we remove it from the list of HTML
block templates until such time as a more robust solution is found.

xmodule/tests/test_resource_templates.py

@@ -18,7 +18,6 @@ class ResourceTemplatesTests(unittest.TestCase):
     def test_templates(self):
         expected = {
             'latex_html.yaml',
-            'zooming_image.yaml',
             'announcement.yaml',
             'anon_user_id.yaml'}
         got = {t['template_id'] for t in TestClass.templates()}
@@ -38,7 +37,6 @@ class ResourceTemplatesTests(unittest.TestCase):
     def test_custom_templates(self):
         expected = {
             'latex_html.yaml',
-            'zooming_image.yaml',
             'announcement.yaml',
             'anon_user_id.yaml'}
         got = {t['template_id'] for t in TestClassResourceTemplate.templates()}