fix(jira): gate the legacy endpoints block in the classic issue templates

[svader0]

Description

When V3_FEATURE_LOCATIONS is on, pushing a finding to JIRA or GitHub returns a 500.

The JIRA description templates have two copies. The Tailwind copy under dojo/templates/issue-trackers/ got a {% if V3_FEATURE_LOCATIONS %} gate that renders finding.locations instead of finding.endpoints. The classic copy under dojo/templates_classic/issue-trackers/ did not. UIPreferenceLoader puts the classic tree first for every user who has not opted into the Tailwind UI, so the ungated copy is what most deployments render.

The ungated block does {% if finding.endpoints.all %}. A tenant migrated to Locations keeps its legacy Endpoint rows on purpose, so that queryset hydrates a deprecated Endpoint and Endpoint.__init__ raises NotImplementedError.

This PR copies the same gate into both classic templates:

• dojo/templates_classic/issue-trackers/jira_full/jira-description.tpl
• dojo/templates_classic/issue-trackers/jira_full/jira-finding-group-description.tpl

The group template gets it too. jira_description() renders that one for a finding-group push, and it carried the identical ungated block.

jira_description() and github_body() already pass V3_FEATURE_LOCATIONS into the context, so no Python change is needed.

Test results

Two tests in unittests/test_endpoint_init_v3.py already covered this and were failing:

• TestEndpointInitV3.test_jira_description_renders_locations_under_v3
• TestEndpointInitV3.test_github_body_renders_locations_under_v3

Before, with DD_V3_FEATURE_LOCATIONS=True:

Ran 2 tests
FAILED (errors=2)
NotImplementedError: Endpoint model is deprecated when V3_FEATURE_LOCATIONS is enabled
  File "dojo/jira/helper.py", line 765, in jira_description
    description = render_to_string(template, kwargs)
  ...
  File "django/template/defaulttags.py", line 326, in render
    if match:

After:

Ran 2 tests
OK

unittests/test_jira_helper.py still passes (47 tests). No test asserts the rendered description text, so nothing else changes.

Documentation

No documentation change. This restores the behavior the Locations docs already describe.