[Improvement] possible ClassCastException in JdbcCatalogMetricsSource

### What would you like to be improved?

JdbcCatalogMetricsSource.registerDatasourceMetrics(DataSource dataSource) currently performs an unconditional cast to BasicDataSource. This makes the method unsafe for any valid DataSource implementation, and it can fail at runtime with a ClassCastException. The improvement needed is to make datasource metric registration robust across non-DBCP DataSource instances, or at minimum fail safely.

### How should we improve?

Update registerDatasourceMetrics to handle non-BasicDataSource inputs safely, rather than casting directly.

Here's a unit test to show the issue:
```
public class TestJdbcCatalogMetricsSource {

@Test
public void testRegisterDatasourceMetricsWithNonBasicDataSource() {
JdbcCatalogMetricsSource source = new JdbcCatalogMetricsSource("metalake", "catalog");

DataSource nonBasicDataSource =
new DataSource() {
@Override
public Connection getConnection() {
return null;
}

@Override
public Connection getConnection(String username, String password) {
return null;
}

@Override
public PrintWriter getLogWriter() {
return null;
}

@Override
public void setLogWriter(PrintWriter out) {}

@Override
public void setLoginTimeout(int seconds) {}

@Override
public int getLoginTimeout() {
return 0;
}

@Override
public Logger getParentLogger() throws SQLFeatureNotSupportedException {
return Logger.getGlobal();
}

@Override
public T unwrap(Class iface) throws SQLException {
throw new SQLException("Not a wrapper");
}

@Override
public boolean isWrapperFor(Class iface) {
return false;
}
};

Assertions.assertDoesNotThrow(() -> source.registerDatasourceMetrics(nonBasicDataSource));
}
}
```