Add environment scope on gitlab project variables (#1197)

* add environment scope on gitlab project variables

* fix sanity code

* apply again test

* environment_scope not defined by default. compatible with old versions of lib.

* environment_scope must be optional

* add changelog

* Update changelogs/fragments/1197_gitlab_project_variable.yml

Co-authored-by: Felix Fontein <felix@fontein.de>

Co-authored-by: Felix Fontein <felix@fontein.de>

tests/integration/targets/gitlab_project_variable/tasks/main.yml

@@ -218,6 +218,36 @@
     that:
       - gitlab_project_variable_state is not changed
 
+- name: change environment scope
+  gitlab_project_variable:
+    api_url: "{{ gitlab_host }}"
+    api_token: "{{ gitlab_login_token }}"
+    project: "{{ gitlab_project_name }}"
+    vars:
+      ACCESS_KEY_ID:
+        environment_scope: testing
+  register: gitlab_project_variable_state
+
+- name: state must be changed
+  assert:
+    that:
+      - gitlab_project_variable_state is changed
+
+- name: apply again the environment scope change 
+  gitlab_project_variable:
+    api_url: "{{ gitlab_host }}"
+    api_token: "{{ gitlab_login_token }}"
+    project: "{{ gitlab_project_name }}"
+    vars:
+      ACCESS_KEY_ID:
+        environment_scope: testing
+  register: gitlab_project_variable_state
+
+- name: state must not be changed
+  assert:
+    that:
+      - gitlab_project_variable_state is not changed
+            
 - name: purge all variables at the beginning
   gitlab_project_variable:
     api_url: "{{ gitlab_host }}"