Fix typo in GNSR

[staabm]

./typos
jq: jq-1.7
$ ./typos README.md src/
Warning: "Righ" should be "Right".
Warning: "Righ" should be "Right".
Warning: "Righ" should be "Right".
error: `Righ` should be `Right`
    ╭▸ src/Analyser/Generator/ExprHandler/ClosureHandler.php:129:15
    │
129 │                     $inAssignRighSideExprTypeResult = yield new TypeExprRequest($inAssignRightSideExpr);
    ╰╴                             ━━━━
error: `Righ` should be `Right`
    ╭▸ src/Analyser/Generator/ExprHandler/ClosureHandler.php:130:40
    │
130 │                     $inAssignRightSideType = $inAssignRighSideExprTypeResult->type;
    ╰╴                                                      ━━━━
error: `Righ` should be `Right`
    ╭▸ src/Analyser/Generator/ExprHandler/ClosureHandler.php:141:46
    │
141 │                     $inAssignRightSideNativeType = $inAssignRighSideExprTypeResult->nativeType;
    ╰╴                                                            ━━━━

[ondrejmirtes]

Thank you!