[BUG] FEATURE_MATRIX shows JPMorgan does not support Refunds

I added support for refunds 3 weeks ago in #8436. Feature matrix needs to be updated.
<think>
PR Context:
- Title: fix(feature_matrix): refunds are supported by jpmorgan
- Merged: 2025-07-24T13:32:53Z
- Files changed: 1 files
- Commits: 1 commits

Implementation approach:
## Type of Change
<!-- Put an `x` in the boxes that apply -->

- [x] Bugfix
- [ ] New feature
- [ ] Enhancement
- [ ] Refactoring
- [ ] Dependency updates
- [ ] Documentation
- [ ] CI/CD

## Description
<!-- Describe your changes in detail -->

This PR marks refunds as supported by JPMorgan connector. Although this does not affect refund flow, the feature matrix marking is wrong. 

### Additional Changes

- [ ] This PR modifies the API contract
- [ ] This PR modifies the datab
</think>

To implement this, you'll need to modify:


**Detailed Implementation:**


**Commit 1:** fix(feature_matrix): refunds are supported by jpmorgan (#8699)
Files to modify:


**crates/hyperswitch_connectors/src/connectors/jpmorgan.rs**
  Modify existing code