fix: Linux support for localnet script

[zotho]

On Linux:

make localnet-build
...
./localnet/build-docker.sh: line 17: docker-compose: command not found

# Version I'm running:
docker compose version
Docker Compose version v2.26.1

make localnet-init
# Got a lot errors in the output...
sed: can't read s/\(persistent_peers *= *"\).*\(" *\)/\1 [email protected]:26656,[email protected]:26656\2/: No such file or directory
sed: can't read s/moniker = "localtestnet"/moniker = "validator03"/g: No such file or directory

I've add check for $OSTYPE variable and replaced docker-compose -> docker compose.

[HarmlessEvil]

I don't really like that we copy-pasted exactly the same commands twice. We can store the command in variable like this:

# Check if we are on macOS
if [[ "$OSTYPE" == "darwin"* ]]; then
    SED_COMMAND="sed -i ''"
else
    SED_COMMAND="sed -i"
fi

And then use it like this:

$SED_COMMAND '/\[api\]/,+3 s/enable = false/enable = true/' $MAIN_PATH_CONFIG/app.toml

[jilio]

Hey @valli0x
Same here. Please review this PR. If it's still useful, please resolve conflicts and rebase it. If not, let's close it.