[.gitlab-ci.yml] Always start CI manually

In order to avoid unnecessary pipelines

.gitlab-ci.yml

@@ -48,7 +48,7 @@ pica-ci-base:
     - if: '$CI_COMMIT_BRANCH == "master" || $CI_COMMIT_BRANCH == "dev-ci"'
       changes:
         - "pica-ci-base/**"
-      when: always
+      when: manual
 
 # Create a file a few environment variables added (which Dockerfile has been modified, the complete name of the image...)
 # The file will be an artifact shared with further steps
@@ -65,7 +65,7 @@ set-variables:
     - changes:
       - "pica-*/**"
       - "meta-*/**"
-      when: always
+      when: manual
 
 # Build the image that was modified
 build:
@@ -91,7 +91,7 @@ build:
     - changes:
       - "pica-*/Dockerfile"
       - "meta-*/Dockerfile"
-      when: always
+      when: on_success
     - changes:
       - "pica-*/**"
       - "meta-*/**"