Fix version check for search pipelines REST test

As @reta pointed out, these tests should be skipped for versions less
than 2.7.0, but the skip version ranges are inclusive. So, the upper
bound of the range should be 2.6.99.

This brings a change made for
opensearch-project#7589 onto the main
branch.

ssssss-off-by: Michael Froh <froh@amazon.com>

Author: msfroh

rest-api-spec/src/main/resources/rest-api-spec/test/search_pipeline/10_basic.yml

@@ -1,7 +1,7 @@
 ---
 "Test basic pipeline crud":
   - skip:
-      version: " - 2.7.0"
+      version: " - 2.6.99"
       reason: "Added in 2.7.0"
   - do:
       search_pipeline.put:
@@ -32,7 +32,7 @@
 ---
 "Test Put Versioned Pipeline":
   - skip:
-      version: " - 2.7.0"
+      version: " - 2.6.99"
       reason: "Added in 2.7.0"
   - do:
       search_pipeline.put:
@@ -125,7 +125,7 @@
 ---
 "Test Get All Pipelines":
   - skip:
-      version: " - 2.7.0"
+      version: " - 2.6.99"
       reason: "Added in 2.7.0"
   - do:
       search_pipeline.put:
@@ -152,7 +152,7 @@
 ---
 "Test invalid config":
   - skip:
-      version: " - 2.7.0"
+      version: " - 2.6.99"
       reason: "Added in 2.7.0"
   - do:
       catch: /parse_exception/