Don't do dist-upgrade except on rolling configurations

Author: zpostfacto

.github/update-packages/ubuntu.sh

@@ -9,6 +9,10 @@ APT_FLAGS=(-q -oDpkg::Use-Pty=0)
 export DEBIAN_FRONTEND=noninteractive
 
 apt-get ${APT_FLAGS[@]} update
-apt-get ${APT_FLAGS[@]} dist-upgrade -y
+
+# Full distro upgrades are opt-in for canary/rolling CI lanes only.
+if [[ "${CI_DIST_UPGRADE:-0}" == "1" ]]; then
+	apt-get ${APT_FLAGS[@]} dist-upgrade -y
+fi
 
 exit 0

.github/workflows/linux-flavors.yml

@@ -26,10 +26,12 @@ jobs:
             os: ubuntu-latest
             docker_image: ubuntu
             docker_tag: jammy
+            ci_dist_upgrade: 0
           - build: ubuntu-noble
             os: ubuntu-latest
             docker_image: ubuntu
             docker_tag: noble
+            ci_dist_upgrade: 0
           #- build: ubuntu-latest
           #  os: ubuntu-latest
           #  docker_image: ubuntu
@@ -38,6 +40,7 @@ jobs:
             os: ubuntu-latest
             docker_image: ubuntu
             docker_tag: rolling
+            ci_dist_upgrade: 1
           #- build: ubuntu-devel
           #  os: ubuntu-latest
           #  docker_image: ubuntu
@@ -46,14 +49,17 @@ jobs:
             os: ubuntu-latest
             docker_image: fedora
             docker_tag: latest
+            ci_dist_upgrade: 0
           - build: archlinux-latest
             os: ubuntu-latest
             docker_image: archlinux
             docker_tag: latest
+            ci_dist_upgrade: 0
           - build: alpine-latest
             os: ubuntu-latest
             docker_image: alpine
             docker_tag: latest
+            ci_dist_upgrade: 0
     steps:
       - uses: actions/checkout@main
       - name: Launch container
@@ -63,7 +69,7 @@ jobs:
           docker exec -e CI_BUILD=1 -e IMAGE=${{ matrix.docker_image }} -e IMAGE_TAG=${{ matrix.docker_tag }} -t github-docker-builder sh .github/preinstall.sh
       - name: Update packages
         run: |
-          docker exec -e CI_BUILD=1 -e IMAGE=${{ matrix.docker_image }} -e IMAGE_TAG=${{ matrix.docker_tag }} -t github-docker-builder bash .github/update-packages.sh
+          docker exec -e CI_BUILD=1 -e IMAGE=${{ matrix.docker_image }} -e IMAGE_TAG=${{ matrix.docker_tag }} -e CI_DIST_UPGRADE=${{ matrix.ci_dist_upgrade }} -t github-docker-builder bash .github/update-packages.sh
       - name: Install dependencies
         run: |
           docker exec -e CI_BUILD=1 -e IMAGE=${{ matrix.docker_image }} -e IMAGE_TAG=${{ matrix.docker_tag }} -t github-docker-builder bash .github/install.sh