[docs] more internal build fixes (#7517)

Author: blinkov

ydb/docs/ru/core/yql/reference/yql-core/syntax/_includes/delete.md

@@ -1,6 +1,6 @@
 # DELETE FROM
 
-{% if backend_name == "YDB" %}
+{% if oss == "true" and backend_name == "YDB" %}
 
 {% note warning %}
 

ydb/docs/ru/core/yql/reference/yql-core/syntax/_includes/replace_into.md

@@ -1,6 +1,6 @@
 # REPLACE INTO
 
-{% if backend_name == "YDB" %}
+{% if oss == "true" and backend_name == "YDB" %}
 
 {% note warning %}
 

ydb/docs/ru/core/yql/reference/yql-core/syntax/_includes/update.md

@@ -1,6 +1,6 @@
 # UPDATE
 
-{% if backend_name == "YDB" %}
+{% if oss == "true" and backend_name == "YDB" %}
 
 {% note warning %}
 

ydb/docs/ru/core/yql/reference/yql-core/syntax/_includes/upsert_into.md

@@ -1,6 +1,6 @@
 # UPSERT INTO
 
-{% if backend_name == "YDB" %}
+{% if oss == "true" and backend_name == "YDB" %}
 
 {% note warning %}