RawFirBuilder: don't convert scripts to prevent exceptions

compiler/fir/raw-fir/light-tree2fir/src/org/jetbrains/kotlin/fir/lightTree/converter/DeclarationsConverter.kt

@@ -104,6 +104,9 @@ class DeclarationsConverter(
                 PROPERTY -> firDeclarationList += convertPropertyDeclaration(it)
                 TYPEALIAS -> firDeclarationList += convertTypeAlias(it)
                 OBJECT_DECLARATION -> firDeclarationList += convertClass(it)
+                SCRIPT -> {
+                    // TODO: scripts aren't supported yet
+                }
             }
         }
 

compiler/fir/raw-fir/psi2fir/src/org/jetbrains/kotlin/fir/builder/RawFirBuilder.kt

@@ -821,6 +821,8 @@ open class RawFirBuilder(
                     }
                 }
                 for (declaration in file.declarations) {
+                    // TODO: scripts aren't supported yet
+                    if (declaration is KtScript) continue
                     declarations += declaration.convert<FirDeclaration>()
                 }
             }