build: Nightly repro build for Ubuntu Noble.

.github/workflows/repro.yml

@@ -0,0 +1,29 @@
+---
+# https://docs.corelightning.org/docs/repro
+name: Repro Build Nightly
+on:
+  schedule:
+    - cron: "0 3 * * *"
+  # TODO: remove after testing
+  push:
+    branches:
+      - 7117-repro-nightly-builds
+jobs:
+  ubuntu-noble:
+    name: Ubuntu Noble Repro build
+    runs-on: ubuntu:noble
+    steps:
+      - name: Git checkout
+        uses: actions/checkout@v2
+
+      - name: Build environment setup
+        run: |
+          echo "Building base image for noble"
+          docker run --rm -v $(pwd):/build ubuntu:noble bash -c "apt-get update && apt-get install -y debootstrap && debootstrap $v /build/noble"
+          tar -C noble -c . | docker import - noble
+
+      - name: Builder image setup
+        run: docker build -t cl-repro-noble - < contrib/reprobuild/Dockerfile.noble
+
+      - name: Build using the builder images
+        run: docker run --rm -v $(pwd):/repo -ti cl-repro-noble