Fixed CI workflows to use correct OSD branch.

Signed-off-by: Thomas Hurney <hurneyt@amazon.com>

Author: AWSHurneyt

.github/workflows/cypress-workflow.yml

@@ -7,7 +7,7 @@ on:
     branches:
       - "*"
 env:
-  OPENSEARCH_DASHBOARDS_VERSION: '2.x'
+  OPENSEARCH_DASHBOARDS_VERSION: '2.16'
   SECURITY_ANALYTICS_BRANCH: '2.x'
 jobs:
   tests:

.github/workflows/unit-tests-workflow.yml

@@ -7,7 +7,7 @@ on:
     branches:
       - "*"
 env:
-  OPENSEARCH_DASHBOARDS_VERSION: '2.x'
+  OPENSEARCH_DASHBOARDS_VERSION: '2.16'
 jobs:
   Get-CI-Image-Tag:
     uses: opensearch-project/opensearch-build/.github/workflows/get-ci-image-tag.yml@main