Issue:
Bug: [BUG] Description for refunds - list is not apt



### Bug Description

https://api-reference.hyperswitch.io/api-reference/refunds/refunds--list

This should be - `Lists all the refunds associated with the merchant, or for a specific payment if payment_id is provided`

Current one implies that it'll return refunds of a payment_id if it is not provided.

### Expected Behavior

It should reflect that refunds accociated with a merchant will be returned if payment_id is missing, otherwise only for that payment_id.

### Actual Behavior

Incorrect message being shown.

### Steps To Reproduce

Visit - https://api-reference.hyperswitch.io/api-reference/refunds/refunds--list



### Context For The Bug

_No response_

### Environment

Are you using hyperswitch hosted version? Yes



### Have you spent some time checking if this bug has been raised before?

- [X] I checked and didn't find a similar issue

### Have you read the Contributing Guidelines?

- [X] I have read the [Contributing Guidelines](https://github.com/juspay/hyperswitch/blob/main/docs/CONTRIBUTING.md)

### Are you willing to submit a PR?

Yes, I am willing to submit a PR!

Pull request description:
## Type of Change

- [ ] Bugfix
- [ ] New feature
- [ ] Enhancement
- [ ] Refactoring
- [ ] Dependency updates
- [x] Documentation
- [ ] CI/CD

## Description
The current description for refund - list is incorrect. Newer one looks more apt.


### Additional Changes

- [ ] This PR modifies the API contract
- [ ] This PR modifies the database schema
- [ ] This PR modifies application configuration/environment variables

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## Motivation and Context
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Closes #6751.

## How did you test it?
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## Checklist
<!-- Put an `x` in the boxes that apply -->

- [ ] I formatted the code `cargo +nightly fmt --all`
- [ ] I addressed lints thrown by `cargo clippy`
- [x] I reviewed the submitted code
- [ ] I added unit tests for my changes where possible


Testing:

Patch:
diff --git a/crates/openapi/src/routes/refunds.rs b/crates/openapi/src/routes/refunds.rs
index 4e096e243a8..0ff0891ee54 100644
--- a/crates/openapi/src/routes/refunds.rs
+++ b/crates/openapi/src/routes/refunds.rs
@@ -115,7 +115,7 @@ pub async fn refunds_update() {}
 
 /// Refunds - List
 ///
-/// Lists all the refunds associated with the merchant or a payment_id if payment_id is not provided
+/// Lists all the refunds associated with the merchant, or for a specific payment if payment_id is provided
 #[utoipa::path(
     post,
     path = "/refunds/list",