AssetsController upgrade from v36 to v38

### What is this about?

The `AssetsController` is behind by two major versions and needs to be updated.
Upgrade from v36 to v38.

[Blocked by NetworkController upgrade](https://github.com/MetaMask/metamask-extension/issues/26911)

### Scenario

n/a

### Design

n/a

### Technical Details

See description

### Threat Modeling Framework

n/a

### Acceptance Criteria

- `AssetsController` is on v38

### Stakeholder review needed before the work gets merged

- [X] Engineering (needed in most cases)
- [ ] Design
- [ ] Product
- [ ] QA (automation tests are required to pass before merging PRs but not all changes are covered by automation tests - please review if QA is needed beyond automation tests)
- [ ] Security
- [ ] Legal
- [ ] Marketing
- [ ] Management (please specify)
- [ ] Other (please specify)

### References

_No response_

Start by reviewing the AssetsController upgrade path and the linked NetworkController upgrade issue, which blocks this work. Confirm the current controller version and identify the existing upgrade pattern before making changes. Done means AssetsController is on v38 and the relevant automation checks pass.

Written by the indexing model from the issue text.