`-language:strictEquality` doesn't check `contains` parameter type

## Compiler version

3.5.0-RC1
with `-language:strictEquality` enabled

## Minimized code

```Scala
@main def hello(): Unit =
  println(Seq[String]().contains(1))
```

## Output

```scala
false
```

## Expectation

I would expect it to not compile because of strict equality and mismatched types.