manifest/build: replace explicit dnf with implicit rpm

The pipelines don't use dnf, only rpm. Let the ones that need it pull it in.

internal/manifest/anaconda.go

@@ -102,6 +102,7 @@ func (p *AnacondaPipeline) anacondaBootPackageSet() []string {
 func (p *AnacondaPipeline) getBuildPackages() []string {
 	packages := p.anacondaBootPackageSet()
 	packages = append(packages,
+		"rpm",
 		"lorax-templates-generic",
 	)
 	return packages

internal/manifest/build.go

@@ -39,7 +39,6 @@ func (p *BuildPipeline) addDependent(dep Pipeline) {
 func (p *BuildPipeline) getPackageSetChain() []rpmmd.PackageSet {
 	// TODO: break apart into individual pipelines
 	packages := []string{
-		"dnf",
 		"selinux-policy-targeted",
 		"coreutils",
 		"systemd",

internal/manifest/commit_server_tree.go

@@ -66,6 +66,7 @@ func (p *OSTreeCommitServerTreePipeline) getPackageSetChain() []rpmmd.PackageSet
 
 func (p *OSTreeCommitServerTreePipeline) getBuildPackages() []string {
 	packages := []string{
+		"rpm",
 		"rpm-ostree",
 	}
 	return packages

internal/manifest/os.go

@@ -167,6 +167,7 @@ func (p *OSPipeline) getPackageSetChain() []rpmmd.PackageSet {
 
 func (p *OSPipeline) getBuildPackages() []string {
 	packages := p.platform.GetBuildPackages()
+	packages = append(packages, "rpm")
 	if p.OSTree != nil {
 		packages = append(packages, "rpm-ostree")
 	}