ci: fix the issue that build_docs label has to be used with regular_test

The deploy_docs_preview used to be in the last stage (deploy), which is
later than the post_check. However the label check in the post_check
stage will fail when build_docs is used without regular test. Move the
deploy_docs_preview to new earlier stage (test_deploy) to fix this.

Also move related job `clang_tidy_deploy` there.

.gitlab-ci.yml

@@ -4,6 +4,7 @@ stages:
   - assign_test
   - host_test
   - target_test
+  - test_deploy
   - post_check
   - deploy
   - post_deploy

tools/ci/config/deploy.yml

@@ -1,4 +1,3 @@
-
 .clang_tidy_deploy_template:
   stage: deploy
   image: $CI_DOCKER_REGISTRY/esp32-ci-env
@@ -26,6 +25,8 @@
 
 clang_tidy_deploy:
   extends: .clang_tidy_deploy_template
+  # Override default stage to happen before the post_check
+  stage: test_deploy
   dependencies:
     - clang_tidy_check
     - clang_tidy_check_all
@@ -103,6 +104,8 @@ push_to_github:
 # deploys docs to CI_DOCKER_REGISTRY webserver, for internal review
 deploy_docs_preview:
   extends: .deploy_docs_template
+  # Override default stage to happen before the post_check
+  stage: test_deploy
   only:
     refs:
       - triggers