Draft: Read previous datetime from env

Related to management#821 (closed)

Reimplement incremental mode reading "FROM_DATETIME" env variable instead of opening the previous table of contents XML file in Git.

TODO before merging

• restore .gitlab-ci.yml

.gitlab-ci.yml

@@ -64,9 +64,6 @@ job:
 
 build:
   stage: build
-  only:
-    - changes
-    - master
   except:
     - schedules
   image: