As some of the comments indicated, your this reference is not typed because you are using the function () {} syntax to define your function. The this object inside such a function will inherently be of type any , because this will be the caller of the function (unknowable at design-time).
If you change your syntax to an arrow function, like
pages = () => {
or simply omit the function keyword and arrow altogether, like
pages() {
then the this object inside the function will reference the class instance this instead of type any.
See the TypeScript handbook for more explanation.