chore: add go:fix inline to deprecated client.New

Add a go:fix inline directive to client.New so Go 1.26 can
automatically rewrite callers to NewClient().

This keeps the deprecated wrapper in place while making migration
easier for library users.

client/client.go

@@ -22,6 +22,8 @@ type Client struct {
 // New returns a new Miniflux client.
 //
 // Deprecated: use NewClient instead.
+//
+//go:fix inline
 func New(endpoint string, credentials ...string) *Client {
 	return NewClient(endpoint, credentials...)
 }