feat: remember to split output string

Signed-off-by: kjuulh <contact@kjuulh.io>

crates/cuddle-ci/src/rust_service.rs

@@ -369,6 +369,10 @@ impl MainAction for RustService {
             ))
             .await?;
 
+        let (_, image_tag) = image_tag
+            .split_once(':')
+            .ok_or(eyre::anyhow!("failed to split image tag at :"))?;
+
         ctx.set_image_tag(image_tag)?;
 
         if self.deployment {