Support resolving dependencies of Function packages

This fixes the PackageDependencyManager to allow Function packages to
depend on other packages. Previously this wasn't supported because we
never tried to parse a Function package's package metadata when loading
dependencies.

I'm guessing no-one noticed this because no-one tried to make a function
package with dependencies. I think doing so is valid though - e.g. a
function that's hardcoded to compose resources from a specific provider
should depend on that provider.

Signed-off-by: Nic Cope <[email protected]>

Author: negz

internal/controller/pkg/revision/dependency.go

@@ -73,13 +73,13 @@ func NewPackageDependencyManager(c client.Client, nd dag.NewDAGFn, t v1beta1.Pac
 }
 
 // Resolve resolves package dependencies.
-func (m *PackageDependencyManager) Resolve(ctx context.Context, pkg runtime.Object, pr v1.PackageRevision) (found, installed, invalid int, err error) { //nolint:gocognit // TODO(negz): Can this be refactored for less complexity?
+func (m *PackageDependencyManager) Resolve(ctx context.Context, meta runtime.Object, pr v1.PackageRevision) (found, installed, invalid int, err error) { //nolint:gocognit // TODO(negz): Can this be refactored for less complexity?
 	// If we are inactive, we don't need to resolve dependencies.
 	if pr.GetDesiredState() == v1.PackageRevisionInactive {
 		return 0, 0, 0, nil
 	}
 
-	pack, ok := xpkg.TryConvertToPkg(pkg, &pkgmetav1.Provider{}, &pkgmetav1.Configuration{})
+	pack, ok := xpkg.TryConvertToPkg(meta, &pkgmetav1.Provider{}, &pkgmetav1.Function{}, &pkgmetav1.Configuration{})
 	if !ok {
 		return found, installed, invalid, errors.New(errNotMeta)
 	}