reverting deletiong of Docker, it was not the issue

Dockerfile

@@ -0,0 +1,11 @@
+FROM debian:stable
+
+RUN apt update -y          \
+    && apt upgrade -y      \
+    && apt install -y build-essential valgrind
+
+WORKDIR /root/
+
+COPY valgrind.sh /root/valgrind.sh
+
+ENTRYPOINT ["./valgrind.sh"]

action.yml

@@ -30,8 +30,5 @@ inputs:
     default: false
 
 runs:
-  using: "composite"
-  steps:
-    - name: "Run Valgrind checker"
-        run: valgrind.sh
-        shell: bash
+  using: "docker"
+  image: "Dockerfile"

docker-compose.yml

@@ -0,0 +1,13 @@
+version: "3.9"
+
+services:
+  valgrind-action:
+    build:
+      dockerfile: Dockerfile
+      context: .
+    image: valgrind-action
+    container_name: valgrind-tester
+    env_file:
+      - .env
+    volumes:
+      - ./:/root/

valgrind.sh

@@ -52,7 +52,7 @@ parse_valgrind_reports() {
     while IFS= read -r line; do
         if [[ "${error}" != "" ]]; then
             if [[ $(echo "${line}" | grep '^==.*== $') && $(skip_criterion_pipe_leaks "${error}") == "1" ]]; then
-                echo "::${kind} title=Valgrind Report::${error}" >> annotations
+                echo "::${kind} title=Valgrind Report::${error}"
                 error=""
                 status=1
             else