Unmute the test failure: painless/71_context_api (#60758)

I was unable to reproduce this locally on either 7.6 (first introduced) and 7.x. This is already not muted 
on master and doesn't appear to have failures. There were some API changes at the time that could 
have affected this test, and I'm wondering with backports if this is now stable again. If this has more 
failures, I will continue to investigate further.

Relates to #51939

modules/lang-painless/src/yamlRestTest/resources/rest-api-spec/test/painless/71_context_api.yml

@@ -1,7 +1,4 @@
 "Action to list contexts":
-    - skip:
-        version: "all"
-        reason: "AwaitsFix https://github.com/elastic/elasticsearch/issues/51939"
     - do:
         scripts_painless_context: {}
     - match: { contexts.0: aggregation_selector}
@@ -9,9 +6,6 @@
 ---
 
 "Action to get all API values for score context":
-    - skip:
-        version: "all"
-        reason: "AwaitsFix https://github.com/elastic/elasticsearch/issues/51939"
     - do:
         scripts_painless_context:
             context: score