Fix @graph @container term @context handling.

When a term scoped context is nullified, it also nullifies the container
information. This fix gets the `@container` value from the active
context. In particular, this is needed for proper `@graph` container
handling.

Author: davidlehn

CHANGELOG.md

@@ -1,5 +1,10 @@
 # jsonld ChangeLog
 
+## 8.3.2 - 2023-xx-xx
+
+### Fixed
+- Fix handling of a `@graph` `@container` term that has a `null` `@context`.
+
 ## 8.3.1 - 2023-09-06
 
 ### Fixed

lib/expand.js

@@ -856,7 +856,7 @@ async function _expandObject({
       });
     }
 
-    const container = _getContextValue(termCtx, key, '@container') || [];
+    const container = _getContextValue(activeCtx, key, '@container') || [];
 
     if(container.includes('@language') && _isObject(value)) {
       const direction = _getContextValue(termCtx, key, '@direction');