Update dependencies and a small memory optimization.

Update deps and add go1.24 to test matrix.

Update go.mod dependencies.

Add EachIter which provides an iterator that can be used in for..range loops on the *Selection object.

goquery now requires Go version 1.23+, use goquery v1.9.x for older Go versions.

Update go.mod dependencies.

Update go.mod dependencies.

Improve allocation of Map, better document cascadia behavior differences.

Note that starting with this release, goquery now requires Go 1.18+. If you need to build with an older Go version, use goquery v1.8.x.

Update go.mod, CI.