remove EEM pages

Author: mdbirnstiehl

reference/observability/elastic-entity-model.md

@@ -1,4 +1,3 @@
 toc:
   - file: index.md
-  - file: fields-and-object-schemas.md
-  - hidden: elastic-entity-model.md
+  - file: fields-and-object-schemas.md

reference/observability/toc.yml

@@ -152,7 +152,6 @@ toc:
                       - file: observability/apm/service-map.md
                       - file: observability/apm/service-overview.md
                       - file: observability/apm/mobile-service-overview.md
-                  - hidden: observability/apm/inventory.md
                   - file: observability/apm/drill-down-into-data.md
                     children:
                       - file: observability/apm/transactions-ui.md