fix: Fix listener stopping on dispose

[mark-kascheev]

Related tasks

Closes https://github.com/surfstudio/flutter-otp-autofill/issues/38

Changes

Missing call of unRegisterBroadcastReceivers()

Checklist for self-check

• [x] Commits and PRs have been filed according to the rules on the project.
• [x] The author is marked as an assigne and assigned mandatory reviewers.
• [x] Required labels marked
• [x] Specified related tasks and/or related PRs.
• [x] Specified Changes.
• [ ] Attached videos/screenshots demonstrating the fix/feature.
• [x] All unspecified fields in the PR description deleted.
• [ ] New code covered by tests.

Checklist for reviewers

• [x] CI passed successfully (with a green check mark).
• [x] PR is atomic, by volume no more than 400 (+-) corrected lines (not including codogen).

Design:

• [x] System design corresponds to the agreements on structure and architecture on the project.
• [x] The code is decomposed into necessary and sufficient components.

Functionality:

• [x] The code solves the problem.
• [x] Any changes to the user interface are reasonable and look good.

Complexity:

• [x] The code is clear, easy to read, functions are small, no more than 50 lines.
• [x] The logic is not overcomplicated, there is no overengineering (no code sections that may be needed in the future, but no one knows about it).

Tests:

• [ ] Updated or added tests for mandatory components.
• [ ] The tests are correct, helpful, and well designed/developed.

Naming:

• [x] The naming of variables, methods, classes and other components is understandable.

Comments:

• [ ] The comments are understandable and helpful.

Documentation:

• [x] All labels are correct
• [ ] Technical documentation updated (after approval, updates last reviewer).

[codecov-commenter]

Codecov Report

Patch and project coverage have no change.

Comparison is base (9ee394c) 96.34% compared to head (4010ea6) 96.34%.

:exclamation: Current head 4010ea6 differs from pull request most recent head 319dc75. Consider uploading reports for the commit 319dc75 to get more accurate results

Additional details and impacted files

```diff @@ Coverage Diff @@ ## main #49 +/- ## ======================================= Coverage 96.34% 96.34% ======================================= Files 4 4 Lines 82 82 ======================================= Hits 79 79 Misses 3 3 ```

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