Adjust BWC rest version for point in time (#62264)

Relates #61872

Author: dnhatn

x-pack/plugin/src/test/resources/rest-api-spec/test/async_search/20-with-poin-in-time.yml

@@ -1,8 +1,8 @@
 ---
 "Async search with point in time":
   - skip:
-      version: " - 7.99.99"
-      reason: "point in time is introduced in 8.0"
+      version: " - 7.9.99"
+      reason: "point in time is introduced in 7.10"
   - do:
       indices.create:
         index: test-1

x-pack/plugin/src/test/resources/rest-api-spec/test/search/point_in_time.yml

@@ -37,8 +37,8 @@ setup:
 ---
 "basic":
   - skip:
-      version: " - 7.99.99"
-      reason: "point in time is introduced in 8.0"
+      version: " - 7.9.99"
+      reason: "point in time is introduced in 7.10"
   - do:
       open_point_in_time:
         index: test
@@ -137,8 +137,8 @@ setup:
 ---
 "wildcard":
   - skip:
-      version: " - 7.99.99"
-      reason: "point in time is introduced in 8.0"
+      version: " - 7.9.99"
+      reason: "point in time is introduced in 7.10"
   - do:
       open_point_in_time:
         index: "t*"