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/distance-matrix/offsets-format/go.go

@@ -12,9 +12,11 @@ func Main() {
 	    Port: 6334,
 	})
 
+	if err != nil { panic(err) } // @hide
+
 	sample := uint64(10)
 	limit := uint64(2)
-	res, err := client.SearchMatrixOffsets(ctx, &qdrant.SearchMatrixPoints{
+	res, err := client.SearchMatrixOffsets(context.Background(), &qdrant.SearchMatrixPoints{
 	    CollectionName: "{collection_name}",
 	    Sample:         &sample,
 	    Limit:          &limit,
@@ -24,4 +26,7 @@ func Main() {
 	        },
 	    },
 	})
+
+	if err != nil { panic(err) } // @hide
+	_ = res // @hide
 }

qdrant-landing/content/documentation/headless/snippets/distance-matrix/offsets-format/rust.rs

@@ -1,7 +1,8 @@
 use qdrant_client::qdrant::{Condition, Filter, SearchMatrixPointsBuilder};
-use qdrant_client::Qdrant;
 
 pub async fn main() -> anyhow::Result<()> {
+    let client = qdrant_client::Qdrant::from_url("http://localhost:6334").build()?; // @hide
+
     client
         .search_matrix_offsets(
             SearchMatrixPointsBuilder::new("collection_name")