Remove beta1 qualifier (opensearch-project#1519) (opensearch-project#1520)

(cherry picked from commit e4fc510)

Signed-off-by: Peter Zhu <zhujiaxi@amazon.com>
Signed-off-by: github-actions[bot] <github-actions[bot]@users.noreply.github.com>
Co-authored-by: github-actions[bot] <github-actions[bot]@users.noreply.github.com>

Author: opensearch-trigger-bot[bot]

build.gradle

@@ -22,7 +22,7 @@ buildscript {
     ext {
         opensearch_version = System.getProperty("opensearch.version", "3.0.0-beta1-SNAPSHOT")
         isSnapshot = "true" == System.getProperty("build.snapshot", "true")
-        buildVersionQualifier = System.getProperty("build.version_qualifier", "beta1")
+        buildVersionQualifier = System.getProperty("build.version_qualifier", "")
         version_tokens = opensearch_version.tokenize('-')
         opensearch_build = version_tokens[0] + '.0'
         plugin_no_snapshot = opensearch_build