rpm: make sure constraints are applied before install

This ensures platform is set in the so we can generate a correct cache
key for dnf cache mounts.

Signed-off-by: Brian Goff <cpuguy83@gmail.com>
(cherry picked from commit 17698bf)
Signed-off-by: Brian Goff <cpuguy83@gmail.com>

Author: cpuguy83

targets/linux/rpm/distro/container.go

@@ -69,10 +69,10 @@ func (cfg *Config) BuildContainer(ctx context.Context, client gwclient.Client, w
 	}
 
 	rootfs = worker.Run(
+		dalec.WithConstraints(opts...), // Make sure constraints (and platform specifically) are applied before install is set
 		cfg.Install(pkgs, installOpts...),
 		llb.AddMount(rpmMountDir, rpmDir, llb.SourcePath("/RPMS")),
 		llb.AddMount(baseMountPath, basePkgs, llb.SourcePath("/RPMS")),
-		dalec.WithConstraints(opts...),
 	).AddMount(workPath, rootfs)
 
 	if post := spec.GetImagePost(targetKey); post != nil && len(post.Symlinks) > 0 {