Fix incorrect cast target

Found while updating #18285 to latest master. Not sure what this fixes, but it was definitely incorrect - `node` must be a `Block` at this point, so this cast must have been intended for `node.parent`, which was checked against `TryStatement` right before it.

Author: weswigham

src/services/refactors/extractSymbol.ts

@@ -375,7 +375,7 @@ namespace ts.refactor.extractSymbol {
                         permittedJumps = PermittedJumps.None;
                         break;
                     case SyntaxKind.Block:
-                        if (node.parent && node.parent.kind === SyntaxKind.TryStatement && (<TryStatement>node).finallyBlock === node) {
+                        if (node.parent && node.parent.kind === SyntaxKind.TryStatement && (<TryStatement>node.parent).finallyBlock === node) {
                             // allow unconditional returns from finally blocks
                             permittedJumps = PermittedJumps.Return;
                         }