spec: Use ExclusiveArch for supported architectures

Only build RPM packages for x86_64 and aarch64, which are the
architectures with full support and testing. This prevents build
failures on ppc64le/s390x where the unit tests fail.
This doesn't block developers from building with cargo on any
architecture for local experimentation.

Signed-off-by: gursewak1997 <gursmangat@gmail.com>

Author: gursewak1997

contrib/packaging/bcvk.spec

@@ -11,8 +11,8 @@ URL:            https://github.com/bootc-dev/bcvk
 Source0:        %{url}/releases/download/v%{version}/bcvk-%{version}.tar.zstd
 Source1:        %{url}/releases/download/v%{version}/bcvk-%{version}-vendor.tar.zstd
 
-# https://fedoraproject.org/wiki/Changes/EncourageI686LeafRemoval
-ExcludeArch:    %{ix86}
+# Only build for architectures with full support and testing
+ExclusiveArch:  x86_64 aarch64
 
 Requires: binutils
 Requires: openssh-clients