[TEST] Reenable disabled tests for _field_caps and _search_shards (#24505)

rest-api-spec/src/main/resources/rest-api-spec/test/field_caps/10_basic.yaml

@@ -169,8 +169,8 @@ setup:
 ---
 "Mix in non-existing field field caps":
   - skip:
-      version: " - 6.0.0" # temporarily disabled
-      reason:  this bug has been fixed in 5.4.0
+      version: " - 5.4.0"
+      reason:  "#24504 fixed a bug in this API in 5.4.1"
 
   - do:
       field_caps:

rest-api-spec/src/main/resources/rest-api-spec/test/search_shards/10_basic.yaml

@@ -14,8 +14,8 @@
 ---
 "Search shards aliases with and without filters":
   - skip:
-      version: " - 6.0.0" # temporarily disabled
-      reason: indices section was added in 5.1.0
+      version: " - 5.4.0"
+      reason: "#24489 fixed a bug that not all aliases where added in 5.4.1 - indices section was added in 5.1.0"
 
   - do:
       indices.create: