runtime-rs: call TomlConfig's validate function after load

Call TomlConfig's validate function after it is loaded and
adjusted by annotations.

Fixes: #5112

Signed-off-by: Bin Liu <bin@hyper.sh>

src/runtime-rs/crates/runtimes/src/manager.rs

@@ -313,6 +313,9 @@ fn load_config(spec: &oci::Spec) -> Result<TomlConfig> {
         TomlConfig::load_from_file(&config_path).context("load toml config")?;
     annotation.update_config_by_annotation(&mut toml_config)?;
 
+    // validate configuration and return the error
+    toml_config.validate()?;
+
     // Sandbox sizing information *may* be provided in two scenarios:
     //   1. The upper layer runtime (ie, containerd or crio) provide sandbox sizing information as an annotation
     //	in the 'sandbox container's' spec. This would typically be a scenario where as part of a create sandbox