ci: remove clang toolchain from prebuilts

Signed-off-by: Olivier Deprez <olivier.deprez@arm.com>
Change-Id: I87d438b50233cc7da083753d701aa29986d66ea2
5588 files changed
tree: a216a7eaff8afd38540ec917790421170606fcce
  1. darwin-x64/
  2. generic/
  3. linux-aarch64/
  4. linux-x64/