> The first project I was able to change their workflow to build inside a 20.04 container.

This approach does _not_ work because you end up with the `node` that runs GitHub Actions not being able to run, certainly this will happen if you end using a sufficiently old container.

> Do you have any documentation or generic recommendations for solving these issues caused by blindly using GitHub Actions for all compilations?

Install these pkgs in an `ubuntu-latest` image:

  - debootstrap debian-archive-keyring
  - software-properties-common
  - schroot fakeroot fakechroot

then

      - name: 'Cache sysroot'
        # This comes after checking out the sources because
        # actions/checkout@v4 cleans $PWD!
        id: cache-sysroot
        uses: actions/cache@v3
        with:
          path: ${{ github.workspace }}/sysroot-DEBIAN_RELEASE
          key: sysroot-DEBIAN_RELEASE-${{ runner.os }}-${{ runner.arch }}-v1

      - name: 'Setup cross-compilation sysroot'
        if: steps.cache-sysroot.oututs.cache-hit != 'true'
        run: |
          set -vx
          SYSROOT_PATH="${{ github.workspace }}/sysroot-DEBIAN_RELEASE"
          echo "SYSROOT_PATH=$SYSROOT_PATH" >> $GITHUB_ENV
          if [ ! -d sysroot-DEBIAN_RELEASE ]; then
            sudo debootstrap --arch=$(dpkg --print-architecture) DEBIAN_RELEASE sysroot-DEBIAN_RELEASE http://archive.ubuntu.com/ubuntu
          fi
          sudo chroot sysroot-DEBIAN_RELEASE apt-get update
          sudo chroot sysroot-DEBIAN_RELEASE apt-get install -y build-essential git wget curl sudo unzip zip autoconf libfreetype6-dev libcups2-dev libx11-dev libxext-dev libxrender-dev libxrandr-dev libxtst-dev libxt-dev libasound2-dev libffi-dev file binutils libfontconfig-dev
          sudo chroot sysroot-DEBIAN_RELEASE apt-get install -y software-properties-common
          sudo chroot sysroot-DEBIAN_RELEASE sudo add-apt-repository ppa:ubuntu-toolchain-r/test
          sudo chown -R $USER:$USER sysroot-DEBIAN_RELEASE

where you replace `DEBIAN_RELEASE` with the release you want to target, and then

  - configure your project's build to use that sysroot.

That's it.

If your project does not support sysroots, make it do so. In general compilers will support sysroots, so it's just a matter of making your build configuration facility support sysroots.