Add workflow and starter scripts

.github/scripts/build_container_images.sh

@@ -0,0 +1,5 @@
+#!/bin/bash
+
+for env_yaml in ./environments/*.yml; do
+   echo "building $env_yaml..."
+done

.github/scripts/install_apptainer.sh

@@ -0,0 +1,11 @@
+#!/bin/bash
+
+set -eo pipefail
+
+wget https://raw.githubusercontent.com/apptainer/apptainer/main/tools/install-unprivileged.sh
+
+chmod +x install-unprivileged.sh
+
+mkdir -p /opt/apptainer
+
+./install-unprivileged.sh /opt/apptainer

.github/workflows/build_containers.yml

@@ -0,0 +1,19 @@
+name: Demo Push
+
+on:
+  pull_request:
+
+jobs:
+  push:
+    runs-on: ubuntu-latest
+    permissions:
+      packages: write
+      contents: read
+    steps:
+      - uses: actions/checkout@v4
+      - name: Install Apptainer
+        run: |
+          .github/scripts/install_apptainer.sh
+      - name: Build images
+        run: |
+          .github/scripts/build_container_images.sh