github: add live upgrade test between stable-{5,6} branches

Signed-off-by: Alexander Mikhalitsyn <aleksandr.mikhalitsyn@canonical.com>

.github/workflows/tests.yml

@@ -101,9 +101,12 @@ jobs:
  matrix:
  compiler:
  - gcc
- - clang
  os:
  - ubuntu-22.04
+ branch:
+ - stable-5.0
+ - stable-6.0
+ - main
  runs-on: ${{ matrix.os }}
  steps:
  - name: Checkout code
@@ -134,8 +137,9 @@ jobs:
  - name: Build upstream head version
  env:
  CC: ${{ matrix.compiler }}
+ BASE_BRANCH: ${{ matrix.branch }}
  run: |
- git clone https://github.com/lxc/lxcfs.git ../upstream-lxcfs
+ git clone -b "${BASE_BRANCH}" https://github.com/lxc/lxcfs.git ../upstream-lxcfs
  cd ../upstream-lxcfs
  meson setup -Ddocs=false -Dtests=true -Dinit-script=systemd -Dprefix=/usr -Db_sanitize=address,undefined build/
  meson compile -C build