tests: Update TestImageTypePipelineNames to be less strict

This test assumed the image's static list of pipeline names must match
the manifest, but it really only needs to check the ones with rpm or
ostree metadata.

To support the ability to have images with different pipelines (eg.
squashfs only vs. ext4+squashfs rootfs iso creation) this changes the
test to make sure the pipelines in the static list are in the manifest,
and in the order specified. But the two lists do not need to match
exactly.

pkg/distro/distro_test.go

@@ -36,6 +36,8 @@ func listTestedDistros(t *testing.T) []string {
 // needed for knowing the names of pipelines from the static object without
 // having access to a manifest, which we need when parsing metadata from build
 // results.
+// NOTE: The static list of pipelines really only needs to include those that
+// have rpm or ostree metadata in them.
 func TestImageTypePipelineNames(t *testing.T) {
 	// types for parsing the opaque manifest with just the fields we care about
 	type rpmStageOptions struct {
@@ -138,11 +140,10 @@ func TestImageTypePipelineNames(t *testing.T) {
 					err = json.Unmarshal(mf, pm)
 					assert.NoError(err)
 
-					assert.Equal(len(allPipelines), len(pm.Pipelines))
+					var pmNames []string
 					for idx := range pm.Pipelines {
-						// manifest pipeline names should be identical to the ones
-						// defined in the image type and in the same order
-						assert.Equal(allPipelines[idx], pm.Pipelines[idx].Name)
+						// Gather the names of the manifest piplines for later
+						pmNames = append(pmNames, pm.Pipelines[idx].Name)
 
 						if pm.Pipelines[idx].Name == "os" {
 							rpmStagePresent := false
@@ -171,6 +172,15 @@ func TestImageTypePipelineNames(t *testing.T) {
 					// sure they match.
 					assert.Equal(imageType.Exports()[0], pm.Pipelines[len(pm.Pipelines)-1].Name)
 
+					// The pipelines named in allPipelines must exist in the manifest, and in the
+					// order specified (eg. 'build' first) but it does not need to be an exact
+					// match. Only the pipelines with rpm or ostree metadata are required.
+					var order int
+					for _, name := range allPipelines {
+						idx := slices.Index(pmNames, name)
+						assert.True(idx >= order, "%s not in order %v", name, pmNames)
+						order = idx
+					}
 				})
 			}
 		}