restore release candidate test

.github/workflows/test-release-candidate.yaml

@@ -0,0 +1,28 @@
+---
+name: Test release candidate
+
+on:
+  pull_request:
+
+jobs:
+  build:
+    name: Test release candidate
+    runs-on: ubuntu-latest
+    steps:
+      -
+        name: Checkout
+        uses: actions/checkout@v3
+      -
+        name: Build test image
+        uses: docker/build-push-action@v4
+        with:
+          context: .
+          file: ./shell/Dockerfile
+          tags: test-image:latest
+          push: false
+      -
+        name: Test
+        uses: addnab/docker-run-action@v3
+        with:
+          image: test-image:latest
+          run: /plcc/tests/run

shell/Dockerfile

@@ -2,12 +2,10 @@
 # We do this in a separate stage so that Git is only installed in this stage
 # and isn't in the final image.
 
-FROM debian:12
+FROM alpine:3
 
 # Install Python 3
-ARG PYTHON3_VERSION=""
-ENV PYTHON3_PACKAGE=python3${PYTHON3_VERSION}
-RUN apk add --no-cache python3${PYTHON3_PACKAGE} \
+RUN apk add --no-cache python3~=3 \
   && python3 -m ensurepip \
   && pip3 install --upgrade pip setuptools \
   && rm -r /usr/lib/python*/ensurepip \
@@ -16,8 +14,7 @@ RUN apk add --no-cache python3${PYTHON3_PACKAGE} \
   && rm -r /root/.cache
 
 # Install JDK
-ARG OPENJDK_VERSION=""
-RUN apk add --no-cache openjdk17-jdk${OPENJDK_VERSION}
+RUN apk add --no-cache openjdk17-jdk~=17
 RUN which java
 ENV JAVA_HOME="/usr/lib/jvm/default-jvm"
 ENV PATH="${JAVA_HOME}/bin:${PATH}"