message: Switch Linux runner to ubuntu-20.04 to unbreak CI
  Earlier today CI started to fail on Linux with a crash during the
  jit mode. Turns out ubuntu-latest switched from ubuntu-20.04 to
  ubuntu-22.04. Let's switch back to ubuntu-20.04 for now to unbreak
  CI until I figured out the root cause.
  cc
diff: @@ -29,7 +29,7 @@ jobs:
  fail-fast: false
  matrix:
  include:
  - - os: ubuntu-latest
  + - os: ubuntu-20.04 # FIXME switch to ubuntu-22.04 once #1303 is fixed
  env:
  TARGET_TRIPLE: x86_64-unknown-linux-gnu
  - os: macos-latest
  