Fix type-checking errors in snippets (code only, no .md)

This commit both:
- Fixes pre-existing mistakes in snippets, aka wrong code samples.
- Adds hidden (`@hide`) statements that do not appear in the docs,
  but satisfy typecheckers.

qdrant-landing/content/documentation/headless/snippets/inference/jinaai-upsert/go.go

@@ -2,7 +2,6 @@ package snippet
 
 import (
 	"context"
-	"time"
 
 	"github.com/qdrant/go-client/qdrant"
 )
@@ -15,7 +14,9 @@ func Main() {
 		UseTLS: true,
 	})
 
-	client.Upsert(ctx, &qdrant.UpsertPoints{
+	if err != nil { panic(err) } // @hide
+
+	client.Upsert(context.Background(), &qdrant.UpsertPoints{
 		CollectionName: "{collection_name}",
 		Points: []*qdrant.PointStruct{
 			{

qdrant-landing/content/documentation/headless/snippets/inference/jinaai-upsert/rust.rs

@@ -1,5 +1,5 @@
 use qdrant_client::{
-    Payload, Qdrant, QdrantError,
+    Payload, Qdrant,
     qdrant::{Image, PointStruct, UpsertPointsBuilder},
 };
 use std::collections::HashMap;