Fix Notification bug during PDF Background Processing

[jakejackson1]

Description

A bug was introduced in 6.11 that skipped the enabled notification checks when using PDF Background Processing. This update reintroduces these checks to verify a notification is active and any conditional logic passes.

Fixes #1554

Testing instructions

1. Enable PDF Background processing in global PDF settings
2. Setup two Notifications on a form and set one to inactive
3. Configure PDF on the form and attach the PDF to both notifications
4. Submit the form
5. Verify only one notification email is sent

Checklist:

• [x] I've tested the code.
• [x] My code is easy to read, follow, and understand
• [ ] My code follows the accessibility standards.
• [x] My code has proper inline documentation / docblocks.

Additional Comments

[codecov[bot]]

Codecov Report

All modified and coverable lines are covered by tests :white_check_mark:

Project coverage is 76.07%. Comparing base (bc81f06) to head (73750a2). Report is 2 commits behind head on development.

Additional details and impacted files

```diff @@ Coverage Diff @@ ## development #1555 +/- ## =============================================== + Coverage 76.02% 76.07% +0.05% =============================================== Files 248 248 Lines 12989 12993 +4 Branches 370 370 =============================================== + Hits 9875 9885 +10 + Misses 3106 3100 -6 Partials 8 8 ```

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