Fix test on unused import suppression

Before the fix for KT-7185, the file looked like:
package suppression
@file:Suppress("UnusedImport")

import java.io.* // unused

And it was parsed incorrectly, because @file: annotations
should come before package directive
But after fix, import directives started being parsed that lead
to wrong unused import (because suppression wasn't parsed still)

idea/testData/inspections/unusedImport/suppression.kt

@@ -1,3 +1,4 @@
 @file:Suppress("UnusedImport")
+package suppression
 
-import java.io.* // unused
+import java.io.* // unused