CI: Enable Erlang problem matchers

.github/workflows/test-make-target.yaml

@@ -54,6 +54,16 @@ jobs:
         # restricted to the build jobs to avoid duplication in output.
         disable_problem_matchers: true
 
+    # We install Erlang problem matchers from ci.erlang.mk.
+    - name: CHECKOUT ERLANG PROBLEM MATCHERS
+      uses: actions/checkout@v4
+      with:
+        repository: ninenines/ci.erlang.mk
+        path: ci.erlang.mk
+
+    - name: INSTALL ERLANG PROBLEM MATCHERS
+      run: echo "::add-matcher::ci.erlang.mk/.github/matchers/erlang-matchers.json"
+
     - name: MIXED CLUSTERS - FETCH SIGNING KEYS
       uses: dsaltares/fetch-gh-release-asset@master
       if: inputs.mixed_clusters