This should no longer be required to build Fuchsia.

This better reflects what the builder actually does.

…iaskrgr

Rollup of 9 pull requests

Successful merges:

 - rust-lang#126822 (Bootstrap command refactoring: port more `Command` usages to `BootstrapCmd` (step 2))
 - rust-lang#126835 (Simplifications in match lowering)
 - rust-lang#126953 (std: separate TLS key creation from TLS access)
 - rust-lang#127045 (Rename `super_predicates_of` and similar queries to `explicit_*` to note that they're not elaborated)
 - rust-lang#127075 (rustc_data_structures: Explicitly check for 64-bit atomics support)
 - rust-lang#127101 (remove redundant match statement from dataflow const prop)
 - rust-lang#127102 (Rename fuchsia builder and bump Fuchsia)
 - rust-lang#127103 (Move binder and polarity parsing into `parse_generic_ty_bound`)
 - rust-lang#127108 (unify `dylib` and `bin_helpers` and create `shared_helpers::parse_value_from_args`)

r? `@ghost`
`@rustbot` modify labels: rollup

Rollup merge of rust-lang#127102 - tmandry:rename-fuchsia-builder, r=Kobzol

Rename fuchsia builder and bump Fuchsia

This PR renames the fuchsia builder as requested in rust-lang/rustc-dev-guide#1989 (review) and bumps Fuchsia.

This includes the quality-of-life improvements for developers in https://fxrev.dev/1061894. It also removes the wasm target, which should speed up the build a little.

The new name of the builder is `x86_64-fuchsia` because I think `x86_64-gnu-fuchsia` would be confusing and put too much emphasis on the host target. (In terms of triples, we are targeting `x86_64-unknown-fuchsia` from `x86_64-unknown-linux-gnu`.) Someone on the infra team should weigh in here.

After this lands, we should update the docs in the rustc-dev-guide again.

cc `@lqd`
r? t-infra

try-job: x86_64-fuchsia