Duplicate identical SQL parameters with set operations

### Bug description

The following code outputs SQL query with two parameters whose values are identical. Query itself doesn't make sense, but it demonstrates the issue.

Code:
```csharp
var query1 = dbContext.Products.Where(x => storeIds.Contains(x.StoreId)).Select(x => x.ProductId);
var query2 = dbContext.Employees.Where(x => storeIds.Contains(x.StoreId)).Select(x => x.EmployeeId);
var query3 = query1.Union(query2);
Console.WriteLine(query3.ToQueryString());
```

Output:
```sql
DECLARE @storeIds1 uniqueIdentifier = '4a3aa2fa-deec-4880-91de-0bfe05d9c272';
DECLARE @storeIds2 uniqueIdentifier = '4a3aa2fa-deec-4880-91de-0bfe05d9c272';

SELECT [p].[product_id]
FROM [products] AS [p]
WHERE [p].[store_id] = @storeIds1
UNION
SELECT [e].[employee_id] AS [product_id]
FROM [employees] AS [e]
WHERE [e].[store_id] = @storeIds2
```

This by itself might be not a big issue, however I have noticed that removing and/or adding navigation properties can eliminate duplicate parameter resulting in a query like this:
```sql
DECLARE @storeIds1 uniqueIdentifier = 'c2232ea2-24b4-4be5-8d63-1d0425d8f435';

SELECT [p].[product_id]
FROM [products] AS [p]
WHERE [p].[store_id] = @storeIds1
UNION
SELECT [e].[employee_id] AS [product_id]
FROM [employees] AS [e]
WHERE [e].[store_id] = @storeIds1
```

This problem wasn't trivial to repeat for me, so I prepared a Visual Studio project where issue can be reproduced:
[Solution1.zip](https://github.com/user-attachments/files/26599379/Solution1.zip)

This also happens on EF Core 8 and EF Core 9, although queries are slightly different.

If this behavior is intentional could you provide an explanation why this is happening?

### Your code

[Solution1.zip](https://github.com/user-attachments/files/26599379/Solution1.zip)

### Stack traces

```text

```

### Verbose output

```text

```

### EF Core version

10.0.5

### Database provider

Microsoft.EntityFrameworkCore.SqlServer

### Target framework

.NET 10.0

### Operating system

Windows 11

### IDE

Visual Studio 2026 18.4.3