Increment version to 3.6.0-SNAPSHOT

Signed-off-by: opensearch-ci-bot <opensearch-infra@amazon.com>

Author: opensearch-ci-bot

build.gradle

@@ -11,7 +11,7 @@ import io.gitlab.arturbosch.detekt.Detekt
 buildscript {
     ext {
         isSnapshot = "true" == System.getProperty("build.snapshot", "true")
-        opensearch_version = System.getProperty("opensearch.version", "3.5.0-SNAPSHOT")
+        opensearch_version = System.getProperty("opensearch.version", "3.6.0-SNAPSHOT")
         buildVersionQualifier = System.getProperty("build.version_qualifier", "")
         version_tokens = opensearch_version.tokenize('-')
         opensearch_build = version_tokens[0] + '.0'