UncheckedIOException

### Affected version

HEAD

### Bug description

There are several UncheckedIOExceptions for issues that can definitely happen, and that are not handled where they should be. E.g.

```
protected Object eval(ScriptEngine engine, ScriptContext context) throws ScriptException {
try (FileReader reader = new FileReader(scriptFile)) {
return engine.eval(reader, context);
} catch (IOException ex) {
throw new UncheckedIOException(scriptFile + " caused:", ex);
}
}
```

This is risky and bug prone. Ideally these should be changed to IOException, but if API compatibility prevents that it looks like most could be replaced with a ScriptException instead.

定位包含 eval 方法和 FileReader/UncheckedIOException 示例的 ScriptEngine 求值代码，然后检查 plugin 中其他 UncheckedIOException 路径。检查每种情况是否可以暴露 IOException，或必须保持与 ScriptException 的 API 兼容性；当不恰当的 unchecked 异常被一致地替换，并且受影响的行为由现有测试套件覆盖时，即表示完成。

由索引模型根据 Issue 内容生成。