Support for Linux on WSL

[roborourke]

Linux on WSL can still use the host.docker.internal host name to resolve the Docker VM, so we need to account for that too when switching between the Docker Engine IP used in Linux vs Linux on WSL.

[hm-backport]

The backport to v6-branch failed:

Commits ["cb390b91a25dbe4bde466a106dc6e7ab44708f77","a3c091aac866840248a0ab58a5485a97e8823313","062e8ae8e263561618c56359a74a46fb2b15c798"] could not be cherry-picked on top of v6-branch

To backport manually, run these commands in your terminal:

# Fetch latest updates from GitHub.
git fetch
# Create new working tree.
git worktree add .worktrees/backport v6-branch
# Navigate to the new directory.
cd .worktrees/backport
# Cherry-pick all the commits of this pull request and resolve the likely conflicts.
git cherry-pick cb390b91a25dbe4bde466a106dc6e7ab44708f77 a3c091aac866840248a0ab58a5485a97e8823313 062e8ae8e263561618c56359a74a46fb2b15c798
# Create a new branch with these backported commits.
git checkout -b backport-304-to-v6-branch
# Push it to GitHub.
git push --set-upstream origin backport-304-to-v6-branch
# Go back to the original working tree.
cd ../..
# Delete the working tree.
git worktree remove .worktrees/backport

Then, create a pull request where the base branch is v6-branch and the compare/head branch is backport-304-to-v6-branch.