### **User description**
<!-- Provide a general summary of your changes in the Title above -->

## Description

handle missed edge case where event handlers are empty.
## Related Issue
Parent task: https://tyktech.atlassian.net/browse/TT-11966
Sub task: https://tyktech.atlassian.net/browse/TT-12064

## Motivation and Context

<!-- Why is this change required? What problem does it solve? -->

## How This Has Been Tested

<!-- Please describe in detail how you tested your changes -->
<!-- Include details of your testing environment, and the tests -->
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etc. -->
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## Screenshots (if appropriate)

## Types of changes

<!-- What types of changes does your code introduce? Put an `x` in all
the boxes that apply: -->

- [x] Bug fix (non-breaking change which fixes an issue)
- [ ] New feature (non-breaking change which adds functionality)
- [ ] Breaking change (fix or feature that would cause existing
functionality to change)
- [ ] Refactoring or add test (improvements in base code or adds test
coverage to functionality)

## Checklist

<!-- Go over all the following points, and put an `x` in all the boxes
that apply -->
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checked. -->
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- [ ] I ensured that the documentation is up to date
- [ ] I explained why this PR updates go.mod in detail with reasoning
why it's required
- [ ] I would like a code coverage CI quality gate exception and have
explained why


___

### **PR Type**
Bug fix, Tests


___

### **Description**
- Added checks and initializations in `event.go` to handle scenarios
where event handlers are empty or undefined, preventing runtime errors.
- Enhanced test coverage in `event_test.go` to include tests for nil and
empty event handlers, ensuring robustness.


___



### **Changes walkthrough** 📝
<table><thead><tr><th></th><th align="left">Relevant
files</th></tr></thead><tbody><tr><td><strong>Bug fix
</strong></td><td><table>
<tr>
  <td>
    <details>
<summary><strong>event.go</strong><dd><code>Handle edge cases and
initialization for empty event handlers</code></dd></summary>
<hr>

apidef/oas/event.go
<li>Added initialization of <code>EventHandlers</code> to handle cases
where event <br>handlers are empty.<br> <li> Ensured
<code>api.EventHandlers.Events</code> is initialized before use to
prevent <br>nil map assignments.<br>


</details>
    

  </td>
<td><a
href="https://github.com/TykTechnologies/tyk/pull/6267/files#diff-528a9f5b311ff21c0b3a9b273e61398209ca8b51550327e4d437bba81e49d577">+6/-5</a>&nbsp;
&nbsp; &nbsp; </td>
</tr>                    
</table></td></tr><tr><td><strong>Tests
</strong></td><td><table>
<tr>
  <td>
    <details>
<summary><strong>event_test.go</strong><dd><code>Extend unit tests for
event handler edge cases</code>&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp;
&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; </dd></summary>
<hr>

apidef/oas/event_test.go
<li>Added test cases for nil and empty event handlers.<br> <li> Modified
existing test cases to include scenarios with pre-existing <br>event
handlers.<br>


</details>
    

  </td>
<td><a
href="https://github.com/TykTechnologies/tyk/pull/6267/files#diff-a1f19f96579a470e73c131a0e37895da0c21d378f6aa48067608274564e62da7">+34/-4</a>&nbsp;
&nbsp; </td>
</tr>                    
</table></td></tr></tr></tbody></table>

___

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