gitlab-ci.yaml: update the branch to releases/2.0.0

Update the CI branch to 2.0.0

Signed-off-by: Marta Rybczynska <marta.rybczynska@linaro.org>

.gitlab-ci.yml

@@ -9,7 +9,7 @@ stages:
 
 include:
  - project: eclipse/oniro-core/oniro
-   ref: kirkstone
+   ref: releases/v2.0.0
    file:
     - .oniro-ci/dco.yaml
     - .oniro-ci/reuse.yaml
@@ -61,7 +61,7 @@ reuse:
     # variables can be changed to CI_PROJECT_URL/CI_COMMIT_SHA when testing
     # changes landing to oniro.git.
     CI_ONIRO_MANIFEST_REPO_URL: https://gitlab.eclipse.org/eclipse/oniro-core/oniro.git
-    CI_ONIRO_MANIFEST_REPO_REV: kirkstone
+    CI_ONIRO_MANIFEST_REPO_REV: releases/v2.0.0
     # URL and branch used with repo "repo --mirror" to speed up workspace
     # construction.
     #
@@ -71,7 +71,7 @@ reuse:
     #
     # The revision should _only_ be bumped during the major release of Oniro.
     CI_ONIRO_MANIFEST_MIRROR_REPO_URL: https://gitlab.eclipse.org/eclipse/oniro-core/oniro.git
-    CI_ONIRO_MANIFEST_MIRROR_REPO_REV: kirkstone
+    CI_ONIRO_MANIFEST_MIRROR_REPO_REV: releases/v2.0.0
     # Directory where repo mirror is constructed. This location is covered by
     # GitLab cache system, and will be reused between pipelines of the same
     # project. Note that the .cache directory name is special.