fix(contentful): properly delete deleted entries and assets

fixes gatsbyjs#5747

packages/gatsby-source-contentful/src/gatsby-node.js

@@ -75,12 +75,17 @@ exports.sourceNodes = async (
   // Remove deleted entries & assets.
   // TODO figure out if entries referencing now deleted entries/assets
   // are "updated" so will get the now deleted reference removed.
+
+  function deleteContentfulNode (node) {
+    const id = normalize.fixId(node.sys.id)
+    const localizedIds = locales.map((locale) => normalize.makeId({ id, currentLocale: locale.code, defaultLocale }))
+    localizedIds.forEach(id => deleteNode(id, getNode(id)))
+  }
+
   currentSyncData.deletedEntries
-    .map(e => e.sys.id)
-    .forEach(id => deleteNode(id, getNode(id)))
+    .forEach(deleteContentfulNode)
   currentSyncData.deletedAssets
-    .map(e => e.sys.id)
-    .forEach(id => deleteNode(id, getNode(id)))
+    .forEach(deleteContentfulNode)
 
   const existingNodes = getNodes().filter(
     n => n.internal.owner === `gatsby-source-contentful`