ci: merge find-files into a single job

this job should work with both merge requests and regular commits

.gitlab-ci.yml

@@ -8,17 +8,15 @@
 # those files. it uses a separate image because
 # markdownlint/markdownlint doesn't ship with git (and runs as a
 # regular user, so we can't install it either)
-find-files-commit:
+find-files:
   stage: build
   image: debian:stable-slim
   script:
     - apt update && apt install -yy --no-install-recommends git ca-certificates
-    - echo "commit SHA $CI_COMMIT_SHA"
+    - export LATEST_COMMIT_SHA="${CI_MERGE_REQUEST_SOURCE_BRANCH_SHA:-${CI_COMMIT_SHA}}"
+    - echo "commit SHA $LATEST_COMMIT_SHA"
     - |
-      echo "working on files... $(git diff-tree --no-commit-id --name-only -r $CI_COMMIT_SHA | tee changed-files.txt)"
-  except:
-    refs:
-      - merge_requests
+      echo "working on files... $(git diff-tree --no-commit-id --name-only -r $LATEST_COMMIT_SHA | tee changed-files.txt)"
   only:
     changes:
       - "*.md"
@@ -28,26 +26,6 @@ find-files-commit:
       - changed-files.txt
     expose_as: 'changed files'
 
-# this is the same as the above, but for merge requests
-find-files-mr:
-  stage: build
-  image: debian:stable-slim
-  script:
-    - apt update && apt install -yy --no-install-recommends git ca-certificates
-    - echo "MR target SHA $CI_MERGE_REQUEST_TARGET_BRANCH_SHA"
-    - |
-      echo "working on files: $(git diff-tree --no-commit-id --name-only -r $CI_MERGE_REQUEST_TARGET_BRANCH_SHA | tee changed-files.txt)"
-  only:
-    refs:
-      - merge_requests
-    changes:
-      - "*.md"
-      - "**/*.md"
-  artifacts:
-    paths:
-      - changed-files.txt
-    expose_as: 'changed files'
-
 # this compares the current repo with the actual wiki to make sure
 # we're not missing any commits, and will fail the push if we need to
 # pull from the wiki