fix(helm): ignore file-not-found error for `helm repo list -o json`

Currently, `helm repo list -o json` returns (either `[]` or an english
"no repositories" error message, depending on whether
`$HELM_CONFIG_HOME/repositories.yaml` exists). This PR aligns the two cases
so that it always returns `[]`.

Signed-off-by: Teo Klestrup Röijezon <teo@nullable.se>

cmd/helm/repo_list.go

@@ -38,8 +38,8 @@ func newRepoListCmd(out io.Writer) *cobra.Command {
 		Args:              require.NoArgs,
 		ValidArgsFunction: noCompletions,
 		RunE: func(cmd *cobra.Command, args []string) error {
-			f, err := repo.LoadFile(settings.RepositoryConfig)
-			if isNotExist(err) || (len(f.Repositories) == 0 && !(outfmt == output.JSON || outfmt == output.YAML)) {
+			f, _ := repo.LoadFile(settings.RepositoryConfig)
+			if len(f.Repositories) == 0 && !(outfmt == output.JSON || outfmt == output.YAML) {
 				return errors.New("no repositories to show")
 			}