Correctly handle vulnerabilities without fixed version

Fixes error thrown by vulnerability without a patched version: https://gitlab.com/dependabot-gitlab/dependabot/-/issues/220+

Potential improvement: Check for vulnerabilities without fixed version and create an issue to raise awareness

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Allure report

allure-report-publisher generated test report!

rspec: ✅ test report for 6d37bdd9

+------------------------------------------------------------------+
|                        behaviors summary                         |
+-------------+--------+--------+---------+-------+-------+--------+
|             | passed | failed | skipped | flaky | total | result |
+-------------+--------+--------+---------+-------+-------+--------+
| jobs        | 14     | 0      | 0       | 0     | 14    | ✅     |
| services    | 170    | 0      | 0       | 0     | 170   | ✅     |
| controllers | 25     | 0      | 0       | 0     | 25    | ✅     |
| models      | 3      | 0      | 0       | 0     | 3     | ✅     |
| system      | 10     | 0      | 0       | 0     | 10    | ✅     |
| tasks       | 8      | 0      | 0       | 0     | 8     | ✅     |
+-------------+--------+--------+---------+-------+-------+--------+
| Total       | 230    | 0      | 0       | 0     | 230   | ✅     |
+-------------+--------+--------+---------+-------+-------+--------+