Checkstyle version 8.1

[Randgalt]

Checkstyle v 9.1 fixes incorrect errors on switch expressions that assign to a variable. E.g.

String s = switch(foo) {
    case A -> "it's a";
    default -> "it's not a";
};

The current version generates an error for this.

[martint]

Merged as 69c1b58692afd618f9f263555338b2340f881f12