chore(kicker): remove env URL mandatory flag

kicker.json

@@ -47,13 +47,11 @@
         {
           "name": "GCP_REVIEW_ENVIRONMENT_SCHEME",
           "description": "The review environment protocol scheme",
-          "default": "https",
-          "mandatory": true
+          "default": "https"
         },
         {
           "name": "GCP_REVIEW_ENVIRONMENT_DOMAIN",
-          "description": "The review environment domain (ex: `noprod-gcloud.domain.com`).\n\nBy default review `environment.url` will be built as `${GCP_REVIEW_ENVIRONMENT_SCHEME}://${$CI_PROJECT_NAME}-${CI_ENVIRONMENT_SLUG}.${GCP_REVIEW_ENVIRONMENT_DOMAIN}`",
-          "mandatory": true
+          "description": "The review environment domain (ex: `noprod-gcloud.domain.com`).\n\nRequired for static environment URLs declaration only (see doc).\n\nBy default review `environment.url` will be built as `${GCP_REVIEW_ENVIRONMENT_SCHEME}://${$CI_PROJECT_NAME}-${CI_ENVIRONMENT_SLUG}.${GCP_REVIEW_ENVIRONMENT_DOMAIN}`"
         },
         {
           "name": "GCP_REVIEW_KEY_FILE",
@@ -80,8 +78,7 @@
         {
           "name": "GCP_INTEG_ENVIRONMENT_URL",
           "type": "url",
-          "description": "The integration environment url including scheme (ex: `https://my-application-integration.noprod-gcloud.domain.com`).\n\nDo not use variable inside variable definition as it will result in a two level cascade variable and gitlab does not allow that.",
-          "mandatory": true
+          "description": "The integration environment url including scheme (ex: `https://my-application-integration.noprod-gcloud.domain.com`).\n\nRequired for static environment URLs declaration only (see doc).\n\nDo not use variable inside variable definition as it will result in a two level cascade variable and gitlab does not allow that."
         },
         {
           "name": "GCP_INTEG_KEY_FILE",
@@ -108,8 +105,7 @@
         {
           "name": "GCP_STAGING_ENVIRONMENT_URL",
           "type": "url",
-          "description": "The staging environment url including scheme (ex: `https://my-application-staging.noprod-gcloud.domain.com`).\n\nDo not use variable inside variable definition as it will result in a two level cascade variable and gitlab does not allow that.",
-          "mandatory": true
+          "description": "The staging environment url including scheme (ex: `https://my-application-staging.noprod-gcloud.domain.com`).\n\nRequired for static environment URLs declaration only (see doc).\n\nDo not use variable inside variable definition as it will result in a two level cascade variable and gitlab does not allow that."
         },
         {
           "name": "GCP_STAGING_KEY_FILE",
@@ -136,8 +132,7 @@
         {
           "name": "GCP_PROD_ENVIRONMENT_URL",
           "type": "url",
-          "description": "The production environment url including scheme (ex: `https://my-application.gcloud.domain.com`).\n\nDo not use variable inside variable definition as it will result in a two level cascade variable and gitlab does not allow that.",
-          "mandatory": true
+          "description": "The production environment url including scheme (ex: `https://my-application.gcloud.domain.com`).\n\nRequired for static environment URLs declaration only (see doc).\n\nDo not use variable inside variable definition as it will result in a two level cascade variable and gitlab does not allow that."
         },
         {
           "name": "AUTODEPLOY_TO_PROD",