pretty test should not specify --crate-type=lib when typechecking

[TimNN]

Since the early days of pretty tests (77be30f) they were compiled as libraries so that they did not require a main function. By now they also run on all the run pass test, which all have a main and there is (or soon will be) at least one run pass test which requires to be compiled as a binary (see #27565).

As discussed shortly on irc (starting here), the best solution seems to be to remove that flag and only add it to those tests which require it.

I'll try to tackle this and get a pull request up soon.

cc @nrc

[TimNN]

Alright, I fixed this pr to account for another pretty test which was added after I first open this pr, it should now build again.