Conditionally run LSIF actions depending on changes
Created by: jhchabran
LSIF GitHub actions are systematically run on every PR, even when there are no changes related to the corresponding language.
Because actions can filtered to only act on specific changes, this can be fixed but it requires splitting them into two separate actions, because we cannot perform that check at job level.
QA
- https://github.com/sourcegraph/sourcegraph/runs/4461865614?check_suite_focus=true
