Add the CI file check to mergify (#283)

I made a mistake in #279, for PRs that modify both .hs an .md the dummy would pass 🙄

Copying the logic to .mergify.yml should fix this. 🤞

.github/workflows/dummy-ci.yml

@@ -1,28 +0,0 @@
-# RUN IN CASE Haskell-CI DOES NOT RUN
-# used for mergify check
-name: Co-Haskell-CI
-on:
-  push: 
-    paths-ignore:
-      - '**.hs'
-      - '**.sw'
-      - '**.cabal'
-      - '*.yaml'
-      - 'data/**.yaml'
-      - 'cabal.project*'
-  # reuse the same filter for pull-requests
-  pull_request:
-    paths-ignore:
-      - '**.hs'
-      - '**.sw'
-      - '**.cabal'
-      - 'stack.yaml'
-      - '*.yaml'
-      - 'data/**.yaml'
-      - 'cabal.project*'
-jobs:
-  linux:
-    runs-on: ubuntu-latest
-    steps:
-      - name: Do nothing
-        run: exit 0

.mergify.yml

@@ -7,7 +7,14 @@ pull_request_rules:
   name: Automatically merge pull requests
   conditions:
   - or:
-    - check-success=Co-Haskell-CI
+    - and:
+      - -files~=\.hs$
+      - -files~=\.sw$
+      - -files~=\.cabal$
+      - -files=stack.yaml
+      - -files~=cabal.project.*
+      - -files~=^[^/]*\.yaml$
+      - -files~=^data/.*\.yaml$
     - and:
       - check-success=Haskell-CI - Linux - ghc-9.0.1
       - check-success=Haskell-CI - Linux - ghc-8.10.4