[build] Disable aarch64 build and remove unused bootstrap binaries. JB#50499

Signed-off-by: David Greaves <david.greaves@jolla.com>

Author: lbt

rust-1.44.0-aarch64-unknown-linux-gnu.tar.gz

@@ -36,7 +36,7 @@
 %global rust_aarch64_triple aarch64-unknown-linux-gnu
 %global rust_x86_triple i686-unknown-linux-gnu
 
-%define build_aarch64 1
+%define build_aarch64 0
 
 %global python python3