The feast registry-dump command fails with PostgreSQL registry (SQL registry type)

## Expected Behavior

According to the official Feast documentation, the `feast registry-dump` command prints the content of the registry.

## Current Behavior

The `feast registry-dump` command does not work when the registry is configured to be PostgreSQL (`registry_type: sql`).
Using a postgres:14 Docker image for the registry makes it fail with the following error raised by the get_registry_store_class_from_scheme(..) function:

```
Exception: Registry path postgresql+psycopg://:@:5432/ has unsupported scheme postgresql+psycopg. Supported schemes are file, s3 and gs.
```

## Steps to reproduce

Set up a local Feast environment in docker compose using PostgreSQL as registry:

```
postgres:
image: postgres:14
environment:
POSTGRES_DB: feast
POSTGRES_PASSWORD: mysecretpassword
POSTGRES_USER: myusername
ports:
- 5435:5432
```

feature_store.yaml:

```
project:
provider: local
entity_key_serialization_version: 2 # it also fails with 3
registry:
registry_type: sql
path: "postgresql+psycopg://myusername:mysecretpassword@postgres:5432/feast"
offline_store:
...
online_store:
...
```

Then try to run the `feast registry-dump` command in this environment.

### Specifications

- Version: 0.54.0 (but should be present in latest version too, as the registry dump logic is unchanged)
- Platform: Debian GNU/Linux 12 (python:3.11.5-slim Docker image with feast lib v0.54.0)
- Subsystem: SQL registry

## Possible Solution

Fix the command so feast registry-dump works with all supported registry backends.
Or, if limiting registry-dump to file/s3/gs registries is intentional, document that restriction clearly in the CLI reference and have the command fail with an explicit, actionable message (e.g. "registry-dump is not supported for SQL registries; use feast list instead") rather than the generic "unsupported scheme" error.

Start by reproducing the failure with the PostgreSQL Docker Compose setup and inspect the feast registry-dump command, especially get_registry_store_class_from_scheme(..). Confirm whether SQL registries should be supported; done means the command works with the PostgreSQL registry or returns a clear, actionable restriction message if they are intentionally unsupported.

Written by the indexing model from the issue text.