[roll] Roll fuchsia [superproject] Roll llvm-project/libc [libc][docs] disable pthreads docs (#123824)

Having a target named pthreads is breaking when multiple runtimes are enabled.
Disable this target for now so that the builds go back to green (and sites get
updated).

Link: llvm/llvm-zorg#359 (comment)
Link: #122006
Link: #122497
Link: #123821
GitOrigin-RevId: 24027cdc12475147504a3774da8310988891b879
Original-Revision: e58422d81dea98c3acd2b044916d905ec13ca781
Original-Reviewed-on: https://fuchsia-review.googlesource.com/c/fuchsia/+/1191992
Original-Revision: e4b1aed038581f10fa4a8f0476cfedaa65329f32
Change-Id: Icbfeb1a3055f2a951c07a7b5575c132abd16fc19

Author: global-integration-roller

stem

@@ -11,7 +11,7 @@
              githooks="integration/git-hooks"
              remote="https://fuchsia.googlesource.com/fuchsia"
              gerrithost="https://fuchsia-review.googlesource.com"
-             revision="4855844d4c9cac83556895dc9dd034ba8a0809fa"/>
+             revision="e4b1aed038581f10fa4a8f0476cfedaa65329f32"/>
   </projects>
   <hooks>
     <hook name="install-environment"