refactor(routing): update configs on updation of mca

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

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

## Description
https://github.com/juspay/hyperswitch/pull/9659
This pull request introduces a new helper function to update the default fallback connector configuration whenever a merchant connector account (MCA) is updated. This ensures that changes to connector status (such as disabling or enabling) are accurately reflected in both merchant and profile configurations. The changes also include necessary imports and function calls to integrate this logic into the connector update flow.

**Connector fallback configuration updates:**

* Added the `update_default_fallback_on_mca_update` function in `routing/helpers.rs` to update merchant and profile default connector configurations based on the status of the updated MCA. The function ensures that disabled or inactive connectors are removed from the defaults, and enabled connectors are added if not already present.
* Integrated the new helper into the `update_connector` flow in `admin.rs`, so it is triggered automatically after connector updates.

**Imports and code organization:**

* Added necessary imports for `update_default_fallback_on_mca_update` and related types in `admin.rs` and `helpers.rs` to support the new logic. [[1]](diffhunk://#diff-7e1b4a44fadc4de1af2a6abeb318b3ddf044177c44ba00731c33dbf4cdce92b7R25-R28) [[2]](diffhunk://#diff-ea48d33e52b2cb7edbbba1d236b55f946fdb2c178f8c76f4226818b3630c4658R6)


### Additional Changes

- [ ] This PR modifies the API contract
- [ ] This PR modifies the database schema
- [ ] This PR modifies application configuration/environment variables


## How did you test it?
<!--
Did you write an integration/unit/API test to verify the code changes?
Or did you test this change manually (provide relevant screenshots)?
-->
1. Create two connectors namely adyen and wise
2. check configs table
```
 SELECT key, config
FROM configs
WHERE key = 'routing_default_po_pro_RTMoW14AvhG5cjmcpcNb';
```
```
 SELECT key, config
FROM configs
WHERE key = 'routing_default_po_merchant_id';
```
3. disable one of them
4. check configs table again for above query, this time the disabled shouldn't be present.
5. Re-enable the disabled connector, then query the table for the connector to be added back.


## Checklist
<!-- Put an `x` in the boxes that apply -->

- [ ] I formatted the code `cargo +nightly fmt --all`
- [ ] I addressed lints thrown by `cargo clippy`
- [ ] I reviewed the submitted code
- [ ] I added unit tests for my changes where possible

<think>
PR Context:
- Title: revert(routing): update configs on updation of mca
- Merged: 2025-10-08T08:46:29Z
- Files changed: 3 files
- Commits: 1 commits

Implementation approach:
Reverts juspay/hyperswitch#9689
</think>

To implement this, you'll need to modify:


**Detailed Implementation:**


**Commit 1:** revert(routing): update configs on updation of mca (#9740)
Files to modify:


**crates/router/src/core/admin.rs**
  Modify existing code

**crates/router/src/core/routing.rs**
  Modify existing code

**crates/router/src/core/routing/helpers.rs**
  Remove:
    - function: pub::redact_cgraph_cache
    - function: pub::redact_routing_cache
    - function: pub::update_default_fallback_on_mca_update
{"issue_number": 9689, "pr_number": 9740, "commits_count": 1, "files_changed": 3, "response_length": 711, "file_count": 5, "needs_breakdown": false}