Add new action step

Author: rrrene

.github/workflows/housekeeping.yml

@@ -65,3 +65,22 @@ jobs:
           elixir-version: 1.16.2
       - run: mix deps.get
       - run: ASSERT_TRIGGERS=1 mix test
+
+  compare_to_latest_credo:
+    name: "resulting issues are still the same (optional)"
+    runs-on: ubuntu-20.04
+    steps:
+      - uses: actions/checkout@v4
+        with:
+          fetch-depth: 0
+      - uses: erlef/setup-beam@v1
+        with:
+          otp-version: 26.2
+          elixir-version: 1.16.2
+      - run: mix deps.get
+      - run: mix credo
+      - run: mkdir tmp
+      - run: elixir test/old_credo.exs > tmp/old_credo.txt
+      - run: mix credo --strict --enable-disabled-checks .+ --no-color --format oneline > tmp/new_credo.txt
+      - run: diff tmp/old_credo.txt tmp/new_credo.txt
+